WEBVTT
ac921801-4673-4330-a447-ea53c9488427/563-0
00:00:03.176 --> 00:00:05.266
It's my pleasure to introduce
Ettore.
ac921801-4673-4330-a447-ea53c9488427/600-0
00:00:05.656 --> 00:00:09.076
He started off his education
across Italy with degrees from
ac921801-4673-4330-a447-ea53c9488427/600-1
00:00:09.076 --> 00:00:12.382
the University of Genoa and
University of Pisa in geology
ac921801-4673-4330-a447-ea53c9488427/600-2
00:00:12.382 --> 00:00:15.403
and geophysics, respectively,
followed by a research
ac921801-4673-4330-a447-ea53c9488427/600-3
00:00:15.403 --> 00:00:17.626
fellowship at the University of
Milan.
ac921801-4673-4330-a447-ea53c9488427/637-0
00:00:17.936 --> 00:00:21.858
He came over to Stanford for his
PhD, which he completed in 2021,
ac921801-4673-4330-a447-ea53c9488427/637-1
00:00:21.858 --> 00:00:25.423
where he worked on a lastic full
waveform inversion for the
ac921801-4673-4330-a447-ea53c9488427/637-2
00:00:25.423 --> 00:00:27.146
Stanford Exploration project.
ac921801-4673-4330-a447-ea53c9488427/672-0
00:00:27.316 --> 00:00:30.273
He moved to Cal Tech for a
postdoc, and now as a researcher
ac921801-4673-4330-a447-ea53c9488427/672-1
00:00:30.273 --> 00:00:33.279
for the Southern California
Hispanic network, pioneering the
ac921801-4673-4330-a447-ea53c9488427/672-2
00:00:33.279 --> 00:00:36.236
use of distributed acoustic
sensing, or DAS, for earthquake
ac921801-4673-4330-a447-ea53c9488427/672-3
00:00:36.236 --> 00:00:36.926
early warning.
ac921801-4673-4330-a447-ea53c9488427/705-0
00:00:37.916 --> 00:00:40.749
We're doing a joint seminar with
earthquakes and volcanoes this
ac921801-4673-4330-a447-ea53c9488427/705-1
00:00:40.749 --> 00:00:43.361
week because Atori will be
talking to us about his imaging
ac921801-4673-4330-a447-ea53c9488427/705-2
00:00:43.361 --> 00:00:44.246
work at Long Valley.
ac921801-4673-4330-a447-ea53c9488427/733-0
00:00:44.496 --> 00:00:47.579
That was published last year in
Science Advances that I thought
ac921801-4673-4330-a447-ea53c9488427/733-1
00:00:47.579 --> 00:00:49.746
would have broad interest from
both centers.
ac921801-4673-4330-a447-ea53c9488427/766-0
00:00:50.416 --> 00:00:53.099
As I understand it, there's some
follow up work to be done yet,
ac921801-4673-4330-a447-ea53c9488427/766-1
00:00:53.099 --> 00:00:55.572
so I doubt this is the last
we'll hear on the subject, and
ac921801-4673-4330-a447-ea53c9488427/766-2
00:00:55.572 --> 00:00:56.536
certainly not the last.
ac921801-4673-4330-a447-ea53c9488427/784-0
00:00:56.546 --> 00:00:59.162
We'll hear about DAS giving the
growing given the growing
ac921801-4673-4330-a447-ea53c9488427/784-1
00:00:59.162 --> 00:01:00.966
interest from the monitoring
community.
ac921801-4673-4330-a447-ea53c9488427/805-0
00:01:01.576 --> 00:01:04.648
But first, I'll turn it over to
Atori to give us the tour of
ac921801-4673-4330-a447-ea53c9488427/805-1
00:01:04.648 --> 00:01:05.806
what he's done already.
ac921801-4673-4330-a447-ea53c9488427/812-0
00:01:05.976 --> 00:01:07.386
So have at.
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00:01:08.366 --> 00:01:08.936
Thank you.
ac921801-4673-4330-a447-ea53c9488427/820-0
00:01:08.946 --> 00:01:09.816
Thank you, Alicia.
ac921801-4673-4330-a447-ea53c9488427/823-0
00:01:10.066 --> 00:01:10.936
Can you hear me?
ac921801-4673-4330-a447-ea53c9488427/827-0
00:01:10.946 --> 00:01:12.056
OK, good.
ac921801-4673-4330-a447-ea53c9488427/830-0
00:01:12.346 --> 00:01:12.556
OK.
ac921801-4673-4330-a447-ea53c9488427/841-0
00:01:13.846 --> 00:01:16.076
And so thank you for having me.
ac921801-4673-4330-a447-ea53c9488427/868-0
00:01:16.136 --> 00:01:20.863
And today, I, as Alicia said,
I'm gonna be talking about the
ac921801-4673-4330-a447-ea53c9488427/868-1
00:01:20.863 --> 00:01:25.666
one or possibly many studies of
the Long Valley Caldera using
ac921801-4673-4330-a447-ea53c9488427/868-2
00:01:25.666 --> 00:01:25.976
Das.
ac921801-4673-4330-a447-ea53c9488427/888-0
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And I have some hints of what
will come next, hopefully soon.
ac921801-4673-4330-a447-ea53c9488427/926-0
00:01:30.886 --> 00:01:34.442
But today I'm going to talk
about how we were able to
ac921801-4673-4330-a447-ea53c9488427/926-1
00:01:34.442 --> 00:01:38.524
understand a little bit more
about this large magmatic system
ac921801-4673-4330-a447-ea53c9488427/926-2
00:01:38.524 --> 00:01:42.212
using a baking distributed
acoustic sensing deployed on
ac921801-4673-4330-a447-ea53c9488427/926-3
00:01:42.212 --> 00:01:44.516
existing telecommunication
fibers.
ac921801-4673-4330-a447-ea53c9488427/978-0
00:01:45.436 --> 00:01:49.931
But before we get into the guts
of this system, let me give you
ac921801-4673-4330-a447-ea53c9488427/978-1
00:01:49.931 --> 00:01:54.355
a little bit of an overview and
even like I, I really like the
ac921801-4673-4330-a447-ea53c9488427/978-2
00:01:54.355 --> 00:01:58.498
idea of trying to get a sense of
the scale of this system,
ac921801-4673-4330-a447-ea53c9488427/978-3
00:01:58.498 --> 00:02:01.026
especially the Long Valley
caldera.
ac921801-4673-4330-a447-ea53c9488427/1041-0
00:02:01.176 --> 00:02:05.480
And I know in the US there it's
many people don't like the term
ac921801-4673-4330-a447-ea53c9488427/1041-1
00:02:05.480 --> 00:02:09.784
super volcanoes, but it gives a
sense of you know the scale and
ac921801-4673-4330-a447-ea53c9488427/1041-2
00:02:09.784 --> 00:02:13.752
many of you have probably like
heard and followed the news
ac921801-4673-4330-a447-ea53c9488427/1041-3
00:02:13.752 --> 00:02:18.056
about the tongue eruption that
happened big in in January 2022.
ac921801-4673-4330-a447-ea53c9488427/1088-0
00:02:18.266 --> 00:02:22.987
And I think it gives a very good
perspective of the scale of and
ac921801-4673-4330-a447-ea53c9488427/1088-1
00:02:22.987 --> 00:02:27.200
the power of volcanoes in
particularly the plume that was
ac921801-4673-4330-a447-ea53c9488427/1088-2
00:02:27.200 --> 00:02:31.703
erupted, the diameter of the
plume was around 650 kilometers,
ac921801-4673-4330-a447-ea53c9488427/1088-3
00:02:31.703 --> 00:02:33.736
which is pretty significant.
ac921801-4673-4330-a447-ea53c9488427/1139-0
00:02:33.826 --> 00:02:37.540
But again, I will put into
perspective respective large
ac921801-4673-4330-a447-ea53c9488427/1139-1
00:02:37.540 --> 00:02:41.319
matic system and in the eruption
generated such a strong
ac921801-4673-4330-a447-ea53c9488427/1139-2
00:02:41.319 --> 00:02:45.431
shockwave that made the entire
Earth atmosphere oscillate and
ac921801-4673-4330-a447-ea53c9488427/1139-3
00:02:45.431 --> 00:02:49.608
it could be measured throughout
the entire planet and multiple
ac921801-4673-4330-a447-ea53c9488427/1139-4
00:02:49.608 --> 00:02:50.006
times.
ac921801-4673-4330-a447-ea53c9488427/1179-0
00:02:50.016 --> 00:02:55.317
As you can see from this plot,
and especially like the National
ac921801-4673-4330-a447-ea53c9488427/1179-1
00:02:55.317 --> 00:03:00.039
Academy of Sciences, I am happy
here published this very
ac921801-4673-4330-a447-ea53c9488427/1179-2
00:03:00.039 --> 00:03:05.505
interesting report on a volcanic
system called erupt and and it's
ac921801-4673-4330-a447-ea53c9488427/1179-3
00:03:05.505 --> 00:03:07.576
very, very comprehensive.
ac921801-4673-4330-a447-ea53c9488427/1222-0
00:03:07.586 --> 00:03:11.431
It talks about a lot of topics
and I found it very important
ac921801-4673-4330-a447-ea53c9488427/1222-1
00:03:11.431 --> 00:03:15.464
because I was able to the came
up at least understand where are
ac921801-4673-4330-a447-ea53c9488427/1222-2
00:03:15.464 --> 00:03:19.561
they fundamental questions that
we would like to answer for this
ac921801-4673-4330-a447-ea53c9488427/1222-3
00:03:19.561 --> 00:03:20.506
kind of system.
ac921801-4673-4330-a447-ea53c9488427/1227-0
00:03:20.976 --> 00:03:22.166
Yeah, for sure.
ac921801-4673-4330-a447-ea53c9488427/1261-0
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We want to achieve a better
option forecasting a lot of
ac921801-4673-4330-a447-ea53c9488427/1261-1
00:03:25.485 --> 00:03:28.972
people in here in US, US are
working a lot on this kind of
ac921801-4673-4330-a447-ea53c9488427/1261-2
00:03:28.972 --> 00:03:29.326
topic.
ac921801-4673-4330-a447-ea53c9488427/1290-0
00:03:30.456 --> 00:03:34.520
Of course, one of the biggest
problem is in trying to improve
ac921801-4673-4330-a447-ea53c9488427/1290-1
00:03:34.520 --> 00:03:38.386
the, you know, estimates of how
much material could erupt.
ac921801-4673-4330-a447-ea53c9488427/1301-0
00:03:38.456 --> 00:03:40.746
Get a given system in a given
system.
ac921801-4673-4330-a447-ea53c9488427/1325-0
00:03:41.496 --> 00:03:44.786
Understand the structure
underneath the feed or
ac921801-4673-4330-a447-ea53c9488427/1325-1
00:03:44.786 --> 00:03:48.966
underneath the the gut or in the
gut of the volcanic system.
ac921801-4673-4330-a447-ea53c9488427/1392-0
00:03:48.976 --> 00:03:52.484
It's very important to
understand the dynamics and and
ac921801-4673-4330-a447-ea53c9488427/1392-1
00:03:52.484 --> 00:03:56.567
in general and the events in the
fundamental science related to
ac921801-4673-4330-a447-ea53c9488427/1392-2
00:03:56.567 --> 00:04:00.330
these systems and in this talk,
I hope I will show you and
ac921801-4673-4330-a447-ea53c9488427/1392-3
00:04:00.330 --> 00:04:03.775
convince you that task it's a
one way that could help
ac921801-4673-4330-a447-ea53c9488427/1392-4
00:04:03.775 --> 00:04:06.836
understanding through imaging
these two points.
ac921801-4673-4330-a447-ea53c9488427/1480-0
00:04:07.896 --> 00:04:11.766
And as I said that, like uh,
this image is just a very
ac921801-4673-4330-a447-ea53c9488427/1480-1
00:04:11.766 --> 00:04:16.058
simple, you know, qualitative
plot where you have the damage
ac921801-4673-4330-a447-ea53c9488427/1480-2
00:04:16.058 --> 00:04:20.562
on the Y axis and the chances of
occurrence on the axis and you
ac921801-4673-4330-a447-ea53c9488427/1480-3
00:04:20.562 --> 00:04:24.572
can see that big volcanoes are
one of the few, you know,
ac921801-4673-4330-a447-ea53c9488427/1480-4
00:04:24.572 --> 00:04:28.231
physical phenomena that can
actually lead to global
ac921801-4673-4330-a447-ea53c9488427/1480-5
00:04:28.231 --> 00:04:32.524
catastrophe or even like a mass
extinction as we know in the
ac921801-4673-4330-a447-ea53c9488427/1480-6
00:04:32.524 --> 00:04:34.986
past from geological evidence
and.
ac921801-4673-4330-a447-ea53c9488427/1513-0
00:04:35.116 --> 00:04:38.128
And that's actually one of the
topic of today is the fact
ac921801-4673-4330-a447-ea53c9488427/1513-1
00:04:38.128 --> 00:04:41.244
trying to understand super
volcanoes that are actually like
ac921801-4673-4330-a447-ea53c9488427/1513-2
00:04:41.244 --> 00:04:43.996
very, very important as I will
show you in a second.
ac921801-4673-4330-a447-ea53c9488427/1524-0
00:04:44.846 --> 00:04:46.936
Again, let's go back to the
scale again.
ac921801-4673-4330-a447-ea53c9488427/1638-0
00:04:46.946 --> 00:04:51.075
I know some people don't like
the term super volcanoes, but if
ac921801-4673-4330-a447-ea53c9488427/1638-1
00:04:51.075 --> 00:04:55.008
he just give a sense of how
large of an eruption food could
ac921801-4673-4330-a447-ea53c9488427/1638-2
00:04:55.008 --> 00:04:58.875
happen or had happened in the
past, and in particular like
ac921801-4673-4330-a447-ea53c9488427/1638-3
00:04:58.875 --> 00:05:03.069
many of you are familiar with,
the Volcanic Accessibility Index
ac921801-4673-4330-a447-ea53c9488427/1638-4
00:05:03.069 --> 00:05:06.936
VI and just to put things into
perspective like the tongue
ac921801-4673-4330-a447-ea53c9488427/1638-5
00:05:06.936 --> 00:05:11.066
option erupted more or less 2 to
6 kilometer cube of material,
ac921801-4673-4330-a447-ea53c9488427/1638-6
00:05:11.066 --> 00:05:14.933
then we saw the size of the
plume, the Long Valley Caldera
ac921801-4673-4330-a447-ea53c9488427/1638-7
00:05:14.933 --> 00:05:18.406
erupted 650 kilometer cube
around 720,000 years ago.
ac921801-4673-4330-a447-ea53c9488427/1680-0
00:05:18.496 --> 00:05:22.206
So it's you can see you can
imagine the scale and for me
ac921801-4673-4330-a447-ea53c9488427/1680-1
00:05:22.206 --> 00:05:26.437
even more interesting like when
I see these numbers, I mean they
ac921801-4673-4330-a447-ea53c9488427/1680-2
00:05:26.437 --> 00:05:29.626
look big, but for me it wasn't
much informative.
ac921801-4673-4330-a447-ea53c9488427/1699-0
00:05:29.636 --> 00:05:35.500
I actually took this number
divided by the area of Los
ac921801-4673-4330-a447-ea53c9488427/1699-1
00:05:35.500 --> 00:05:37.206
Angeles and big.
ac921801-4673-4330-a447-ea53c9488427/1717-0
00:05:37.216 --> 00:05:40.515
You would cover the entire Los
Angeles basin with one kilometer
ac921801-4673-4330-a447-ea53c9488427/1717-1
00:05:40.515 --> 00:05:41.236
make material.
ac921801-4673-4330-a447-ea53c9488427/1724-0
00:05:41.596 --> 00:05:43.236
So that's a lot of stuff.
ac921801-4673-4330-a447-ea53c9488427/1740-0
00:05:43.926 --> 00:05:46.836
That really puts things into
perspective in my opinion.
ac921801-4673-4330-a447-ea53c9488427/1742-0
00:05:46.846 --> 00:05:47.076
Right.
ac921801-4673-4330-a447-ea53c9488427/1763-0
00:05:47.086 --> 00:05:52.453
And then this, you know, random
volumetric number and again it's
ac921801-4673-4330-a447-ea53c9488427/1763-1
00:05:52.453 --> 00:05:53.526
even more so.
ac921801-4673-4330-a447-ea53c9488427/1800-0
00:05:53.536 --> 00:05:57.490
And when I give this talk, I had
this very, very nice place that
ac921801-4673-4330-a447-ea53c9488427/1800-1
00:05:57.490 --> 00:06:01.382
I found online where the company
flag area or the Florian field
ac921801-4673-4330-a447-ea53c9488427/1800-2
00:06:01.382 --> 00:06:03.146
are actually inflating a lot.
ac921801-4673-4330-a447-ea53c9488427/1816-0
00:06:03.156 --> 00:06:05.582
There is a big debate whether
there is going to be an
ac921801-4673-4330-a447-ea53c9488427/1816-1
00:06:05.582 --> 00:06:05.986
eruption.
ac921801-4673-4330-a447-ea53c9488427/1858-0
00:06:05.996 --> 00:06:09.862
Not probably like a super
volcanic eruption, but you know
ac921801-4673-4330-a447-ea53c9488427/1858-1
00:06:09.862 --> 00:06:13.794
it's a real treat, especially
here in the Naples area like
ac921801-4673-4330-a447-ea53c9488427/1858-2
00:06:13.794 --> 00:06:16.726
there are like a 1.5 million
people living.
ac921801-4673-4330-a447-ea53c9488427/1875-0
00:06:16.736 --> 00:06:19.288
So which is kind of crazy that
they build the city there, but
ac921801-4673-4330-a447-ea53c9488427/1875-1
00:06:19.288 --> 00:06:20.316
that's a different story.
ac921801-4673-4330-a447-ea53c9488427/1897-0
00:06:22.066 --> 00:06:24.982
But you know, it's a real
challenge and they still don't
ac921801-4673-4330-a447-ea53c9488427/1897-1
00:06:24.982 --> 00:06:26.056
know what's going on.
ac921801-4673-4330-a447-ea53c9488427/1911-0
00:06:26.066 --> 00:06:28.906
If it's gonna be a, there's
gonna be an eruption or not.
ac921801-4673-4330-a447-ea53c9488427/1932-0
00:06:28.946 --> 00:06:31.654
And that's the reason why we
need to actually understand
ac921801-4673-4330-a447-ea53c9488427/1932-1
00:06:31.654 --> 00:06:32.556
better the systems.
ac921801-4673-4330-a447-ea53c9488427/1941-0
00:06:32.846 --> 00:06:36.456
And they're very complicated
that you can imagine.
ac921801-4673-4330-a447-ea53c9488427/2005-0
00:06:36.526 --> 00:06:40.005
Like you can see these plots of
the uplift over time of few
ac921801-4673-4330-a447-ea53c9488427/2005-1
00:06:40.005 --> 00:06:43.311
systems, there is even the Long
Valley Yellowstone and a
ac921801-4673-4330-a447-ea53c9488427/2005-2
00:06:43.311 --> 00:06:46.674
complete you can see that
sometimes you have a very, very
ac921801-4673-4330-a447-ea53c9488427/2005-3
00:06:46.674 --> 00:06:49.863
strong inflation and an
eruption, sometimes very, very
ac921801-4673-4330-a447-ea53c9488427/2005-4
00:06:49.863 --> 00:06:52.066
strong inflation and nothing
happens.
ac921801-4673-4330-a447-ea53c9488427/2009-0
00:06:52.076 --> 00:06:53.676
So they're very complicated.
ac921801-4673-4330-a447-ea53c9488427/2033-0
00:06:53.686 --> 00:06:57.163
So just uplift itself or surface
deformation is not enough to
ac921801-4673-4330-a447-ea53c9488427/2033-1
00:06:57.163 --> 00:06:59.406
understand the dynamics of this
system.
ac921801-4673-4330-a447-ea53c9488427/2051-0
00:06:59.496 --> 00:07:03.975
That's really what I want to
explain here, and let's go to
ac921801-4673-4330-a447-ea53c9488427/2051-1
00:07:03.975 --> 00:07:05.796
the Long Valley caldera.
ac921801-4673-4330-a447-ea53c9488427/2057-0
00:07:05.806 --> 00:07:07.466
And why is important?
ac921801-4673-4330-a447-ea53c9488427/2072-0
00:07:07.476 --> 00:07:12.191
Again, like many people are
actually like a more familiar
ac921801-4673-4330-a447-ea53c9488427/2072-1
00:07:12.191 --> 00:07:13.166
about these.
ac921801-4673-4330-a447-ea53c9488427/2134-0
00:07:13.216 --> 00:07:17.342
But the point here is the fact
that in the 80s and in other
ac921801-4673-4330-a447-ea53c9488427/2134-1
00:07:17.342 --> 00:07:21.330
times, there has been some times
of crisis or significant
ac921801-4673-4330-a447-ea53c9488427/2134-2
00:07:21.330 --> 00:07:25.730
seismicity, as you can see from
this plot on the top and uplift
ac921801-4673-4330-a447-ea53c9488427/2134-3
00:07:25.730 --> 00:07:29.787
and people were trying to
understand whether there's going
ac921801-4673-4330-a447-ea53c9488427/2134-4
00:07:29.787 --> 00:07:31.506
to be an eruption or not.
ac921801-4673-4330-a447-ea53c9488427/2220-0
00:07:31.736 --> 00:07:36.368
And and that's kind of the goal
of this the and I guess talk try
ac921801-4673-4330-a447-ea53c9488427/2220-1
00:07:36.368 --> 00:07:40.430
to understand a little bit more
about the system and the
ac921801-4673-4330-a447-ea53c9488427/2220-2
00:07:40.430 --> 00:07:44.776
dynamics driving the uplift
hopefully in terms of volcanism,
ac921801-4673-4330-a447-ea53c9488427/2220-3
00:07:44.776 --> 00:07:49.337
just to give you a little bit of
perspective, you know they one
ac921801-4673-4330-a447-ea53c9488427/2220-4
00:07:49.337 --> 00:07:53.327
of the first eruption that
occurred in this area in the
ac921801-4673-4330-a447-ea53c9488427/2220-5
00:07:53.327 --> 00:07:57.531
Long Valley caldera is the glass
Monta Raylite 2.120 point
ac921801-4673-4330-a447-ea53c9488427/2220-6
00:07:57.531 --> 00:07:58.956
8,000,000 years ago.
ac921801-4673-4330-a447-ea53c9488427/2234-0
00:07:59.366 --> 00:08:03.347
Then we had the Bishop task that
actually created the caldera
ac921801-4673-4330-a447-ea53c9488427/2234-1
00:08:03.347 --> 00:08:03.796
itself.
ac921801-4673-4330-a447-ea53c9488427/2251-0
00:08:03.866 --> 00:08:06.736
That happened more or less turn
on 167,000 years ago.
ac921801-4673-4330-a447-ea53c9488427/2303-0
00:08:07.366 --> 00:08:11.532
1000 years ago then we have
these, the resurgent Dome
ac921801-4673-4330-a447-ea53c9488427/2303-1
00:08:11.532 --> 00:08:16.546
eruptions that you can see still
a significant eruption and over
ac921801-4673-4330-a447-ea53c9488427/2303-2
00:08:16.546 --> 00:08:21.251
time actually like this said,
the volcanism shifted from the
ac921801-4673-4330-a447-ea53c9488427/2303-3
00:08:21.251 --> 00:08:26.111
center of the caldera towards
actually like more North S trend
ac921801-4673-4330-a447-ea53c9488427/2303-4
00:08:26.111 --> 00:08:27.576
and were generated.
ac921801-4673-4330-a447-ea53c9488427/2329-0
00:08:27.586 --> 00:08:31.426
Actually, a lot of money in your
creators and I will come back to
ac921801-4673-4330-a447-ea53c9488427/2329-1
00:08:31.426 --> 00:08:33.986
that when we analyze the
subsurface images.
ac921801-4673-4330-a447-ea53c9488427/2408-0
00:08:35.606 --> 00:08:39.256
I think the biggest scientific
debate, if you want on this
ac921801-4673-4330-a447-ea53c9488427/2408-1
00:08:39.256 --> 00:08:43.091
system is the fact that there
are two competing hypothesis to
ac921801-4673-4330-a447-ea53c9488427/2408-2
00:08:43.091 --> 00:08:47.050
understand that the seismicity
and uplift in the area, one that
ac921801-4673-4330-a447-ea53c9488427/2408-3
00:08:47.050 --> 00:08:51.008
is actually I will tell you like
a geological evidence seems to
ac921801-4673-4330-a447-ea53c9488427/2408-4
00:08:51.008 --> 00:08:54.534
suggest is the 2nd boiling
hypothesis which is basically
ac921801-4673-4330-a447-ea53c9488427/2408-5
00:08:54.534 --> 00:08:57.936
like the idea is that you have
this big magma chamber.
ac921801-4673-4330-a447-ea53c9488427/2415-0
00:08:58.006 --> 00:09:01.656
Underground is just slowly
crystallizing.
ac921801-4673-4330-a447-ea53c9488427/2488-0
00:09:01.976 --> 00:09:05.449
Fluids cannot stay in the magma
as the temperature cools down
ac921801-4673-4330-a447-ea53c9488427/2488-1
00:09:05.449 --> 00:09:08.865
and it's magma is crystallizing,
so they have to be released
ac921801-4673-4330-a447-ea53c9488427/2488-2
00:09:08.865 --> 00:09:12.225
because a buoyancy they go
underneath this kind of lead and
ac921801-4673-4330-a447-ea53c9488427/2488-3
00:09:12.225 --> 00:09:15.754
they push the lead, driving the
uplift and then they skip some
ac921801-4673-4330-a447-ea53c9488427/2488-4
00:09:15.754 --> 00:09:18.666
faults on the side generating
also some seismicity.
ac921801-4673-4330-a447-ea53c9488427/2519-0
00:09:19.816 --> 00:09:24.546
The other hypothesis is the fact
that actually it's this one is
ac921801-4673-4330-a447-ea53c9488427/2519-1
00:09:24.546 --> 00:09:29.275
from the Yellowstone tomography
paper and 2415 and is about the
ac921801-4673-4330-a447-ea53c9488427/2519-2
00:09:29.275 --> 00:09:29.866
weather.
ac921801-4673-4330-a447-ea53c9488427/2553-0
00:09:29.876 --> 00:09:34.201
There is actually like an upper
crust raylite partial melting
ac921801-4673-4330-a447-ea53c9488427/2553-1
00:09:34.201 --> 00:09:38.526
that is actually being recharged
and could possibly lead to a
ac921801-4673-4330-a447-ea53c9488427/2553-2
00:09:38.526 --> 00:09:41.386
more substantial eruption in the
system.
ac921801-4673-4330-a447-ea53c9488427/2565-0
00:09:41.936 --> 00:09:43.176
So these are like the true ones.
ac921801-4673-4330-a447-ea53c9488427/2609-0
00:09:43.696 --> 00:09:47.706
And in terms of evidence, as I
said, like a geological evidence
ac921801-4673-4330-a447-ea53c9488427/2609-1
00:09:47.706 --> 00:09:51.465
seems to suggest that this is
actually more like the uplift
ac921801-4673-4330-a447-ea53c9488427/2609-2
00:09:51.465 --> 00:09:54.848
and you know unrest in the
system is driven by fluids
ac921801-4673-4330-a447-ea53c9488427/2609-3
00:09:54.848 --> 00:09:57.416
because we have low temperature
at that.
ac921801-4673-4330-a447-ea53c9488427/2663-0
00:09:57.426 --> 00:10:01.635
Multiple wells have been drilled
and have found in that there is
ac921801-4673-4330-a447-ea53c9488427/2663-1
00:10:01.635 --> 00:10:05.586
low temperature, geochemical
signature of released gas is is
ac921801-4673-4330-a447-ea53c9488427/2663-2
00:10:05.586 --> 00:10:08.888
not pointing to new magma
intrusions and the other
ac921801-4673-4330-a447-ea53c9488427/2663-3
00:10:08.888 --> 00:10:12.514
evidence is that there is no
recenter option within the
ac921801-4673-4330-a447-ea53c9488427/2663-4
00:10:12.514 --> 00:10:13.356
caldera rate.
ac921801-4673-4330-a447-ea53c9488427/2733-0
00:10:14.326 --> 00:10:17.674
On the other side, the physical
evidence that there were like
ac921801-4673-4330-a447-ea53c9488427/2733-1
00:10:17.674 --> 00:10:20.914
some physical evidence from
seismicity, there were pointing
ac921801-4673-4330-a447-ea53c9488427/2733-2
00:10:20.914 --> 00:10:23.829
to the same mechanism on 2nd
boiling, but like from a
ac921801-4673-4330-a447-ea53c9488427/2733-3
00:10:23.829 --> 00:10:27.393
tomographic perspective at least
like the evidence we're not, you
ac921801-4673-4330-a447-ea53c9488427/2733-4
00:10:27.393 --> 00:10:30.849
know the images were not crisp
enough to try to distinguish and
ac921801-4673-4330-a447-ea53c9488427/2733-5
00:10:30.849 --> 00:10:33.926
have corroboration of this
hypothesis of second boiling.
ac921801-4673-4330-a447-ea53c9488427/2778-0
00:10:33.976 --> 00:10:36.929
So from a demographic
perspective, it will still
ac921801-4673-4330-a447-ea53c9488427/2778-1
00:10:36.929 --> 00:10:40.544
lacking this and and again like
the big question is whether
ac921801-4673-4330-a447-ea53c9488427/2778-2
00:10:40.544 --> 00:10:44.039
there is shallow magma in the
upper crust meaning above 5
ac921801-4673-4330-a447-ea53c9488427/2778-3
00:10:44.039 --> 00:10:45.846
kilometer below the sea level.
ac921801-4673-4330-a447-ea53c9488427/2835-0
00:10:47.086 --> 00:10:51.266
And I will show you that you
know, that's in this case it's
ac921801-4673-4330-a447-ea53c9488427/2835-1
00:10:51.266 --> 00:10:55.376
a, it's a new tool as you may
know of you know it's a tool
ac921801-4673-4330-a447-ea53c9488427/2835-2
00:10:55.376 --> 00:10:59.695
that can allow you to transform
telecommunication, fiber, any
ac921801-4673-4330-a447-ea53c9488427/2835-3
00:10:59.695 --> 00:11:03.456
kind of fiber into a dense array
of seismic stations.
ac921801-4673-4330-a447-ea53c9488427/2854-0
00:11:03.666 --> 00:11:07.518
And I think that's really like a
what this seems to be driving
ac921801-4673-4330-a447-ea53c9488427/2854-1
00:11:07.518 --> 00:11:08.496
this excitement.
ac921801-4673-4330-a447-ea53c9488427/2862-0
00:11:08.586 --> 00:11:09.836
There are multiple studies.
ac921801-4673-4330-a447-ea53c9488427/2884-0
00:11:09.846 --> 00:11:13.443
In this case it's imaging, but
there are other studies in other
ac921801-4673-4330-a447-ea53c9488427/2884-1
00:11:13.443 --> 00:11:15.916
fields that are making a pretty
big impact.
ac921801-4673-4330-a447-ea53c9488427/2919-0
00:11:16.196 --> 00:11:20.219
And just to give you a sense and
perspective like this is the
ac921801-4673-4330-a447-ea53c9488427/2919-1
00:11:20.219 --> 00:11:24.047
some of these fiber already
there, it's a, it's the middle
ac921801-4673-4330-a447-ea53c9488427/2919-2
00:11:24.047 --> 00:11:27.486
mile initiative driven by the
California government.
ac921801-4673-4330-a447-ea53c9488427/2960-0
00:11:27.596 --> 00:11:30.688
These are the fibers that are
already there or will be there
ac921801-4673-4330-a447-ea53c9488427/2960-1
00:11:30.688 --> 00:11:33.780
in the near future and just to
give you a sense, we only use
ac921801-4673-4330-a447-ea53c9488427/2960-2
00:11:33.780 --> 00:11:36.466
this small section of the fiber
to do these studies.
ac921801-4673-4330-a447-ea53c9488427/2981-0
00:11:36.476 --> 00:11:40.247
Imagine what we could do if we
had access to multiple of these
ac921801-4673-4330-a447-ea53c9488427/2981-1
00:11:40.247 --> 00:11:40.666
fibers.
ac921801-4673-4330-a447-ea53c9488427/3081-0
00:11:41.076 --> 00:11:44.729
Now that we're gonna be
abandoned in stations because
ac921801-4673-4330-a447-ea53c9488427/3081-1
00:11:44.729 --> 00:11:48.856
station actually played a role
in this study to relocate the
ac921801-4673-4330-a447-ea53c9488427/3081-2
00:11:48.856 --> 00:11:53.118
events, but just to give you a
sense of the field work that we
ac921801-4673-4330-a447-ea53c9488427/3081-3
00:11:53.118 --> 00:11:56.974
did, we in we make it in a 2021
when I joined Caltech, I
ac921801-4673-4330-a447-ea53c9488427/3081-4
00:11:56.974 --> 00:12:01.033
installed 2 opticians, plexes
units in the Long Valley one,
ac921801-4673-4330-a447-ea53c9488427/3081-5
00:12:01.033 --> 00:12:05.159
they both of the units are, you
know located here in Mammoth
ac921801-4673-4330-a447-ea53c9488427/3081-6
00:12:05.159 --> 00:12:09.286
Lakes and the Red Line is a
telecommunication fiber owned by
ac921801-4673-4330-a447-ea53c9488427/3081-7
00:12:09.286 --> 00:12:11.856
a company there crossing the
caldera.
ac921801-4673-4330-a447-ea53c9488427/3108-0
00:12:11.866 --> 00:12:15.687
As you can see, and one is
sending light north, the other
ac921801-4673-4330-a447-ea53c9488427/3108-1
00:12:15.687 --> 00:12:19.376
One South and at that time the
range was 50 kilometers.
ac921801-4673-4330-a447-ea53c9488427/3138-0
00:12:19.386 --> 00:12:24.069
I will tell you actually now the
range is twice as much for each
ac921801-4673-4330-a447-ea53c9488427/3138-1
00:12:24.069 --> 00:12:28.176
instrument and we had ten 5000
channels every 10 meters.
ac921801-4673-4330-a447-ea53c9488427/3158-0
00:12:28.186 --> 00:12:31.181
We basically record the strain
of these fiber using this single
ac921801-4673-4330-a447-ea53c9488427/3158-1
00:12:31.181 --> 00:12:31.696
instrument.
ac921801-4673-4330-a447-ea53c9488427/3193-0
00:12:31.706 --> 00:12:35.640
Just two instrument simply write
the 100 Hertz, which is kind of
ac921801-4673-4330-a447-ea53c9488427/3193-1
00:12:35.640 --> 00:12:39.090
normal for a station just like
station data and for this
ac921801-4673-4330-a447-ea53c9488427/3193-2
00:12:39.090 --> 00:12:42.176
specific setting we have more
than two years data.
ac921801-4673-4330-a447-ea53c9488427/3208-0
00:12:42.186 --> 00:12:44.286
But we also have two years data
for the longer range.
ac921801-4673-4330-a447-ea53c9488427/3266-0
00:12:44.516 --> 00:12:48.289
I would tell you more later,
just to give you a sense of, you
ac921801-4673-4330-a447-ea53c9488427/3266-1
00:12:48.289 --> 00:12:52.122
know, the beauty in a sense and
the resolution power of the US
ac921801-4673-4330-a447-ea53c9488427/3266-2
00:12:52.122 --> 00:12:56.077
and you can see this is actually
the Antelope Valley magnitude 6
ac921801-4673-4330-a447-ea53c9488427/3266-3
00:12:56.077 --> 00:12:58.876
earthquake that was recorded
from this array.
ac921801-4673-4330-a447-ea53c9488427/3283-0
00:12:58.946 --> 00:13:04.023
We published another study using
this earthquake and you can see
ac921801-4673-4330-a447-ea53c9488427/3283-1
00:13:04.023 --> 00:13:05.976
the richness of the data.
ac921801-4673-4330-a447-ea53c9488427/3344-0
00:13:06.486 --> 00:13:10.021
Of course, this is 100
kilometers at 110 meter spacing,
ac921801-4673-4330-a447-ea53c9488427/3344-1
00:13:10.021 --> 00:13:13.935
so we have 10,000 channel more
or less and this is the P wave
ac921801-4673-4330-a447-ea53c9488427/3344-2
00:13:13.935 --> 00:13:17.597
as wave we have near surface
catering which is I think is
ac921801-4673-4330-a447-ea53c9488427/3344-3
00:13:17.597 --> 00:13:21.637
actually like the strongest part
of the way that we record with
ac921801-4673-4330-a447-ea53c9488427/3344-4
00:13:21.637 --> 00:13:21.826
us.
ac921801-4673-4330-a447-ea53c9488427/3361-0
00:13:21.836 --> 00:13:24.941
Most of the energy you can see
these scattered waves because of
ac921801-4673-4330-a447-ea53c9488427/3361-1
00:13:24.941 --> 00:13:25.766
the near surface.
ac921801-4673-4330-a447-ea53c9488427/3391-0
00:13:25.936 --> 00:13:29.031
Iterate generalities and there
is another thing that it would
ac921801-4673-4330-a447-ea53c9488427/3391-1
00:13:29.031 --> 00:13:32.126
be interested in the future is
to have a look at attenuation.
ac921801-4673-4330-a447-ea53c9488427/3400-0
00:13:32.136 --> 00:13:34.486
Maybe in triplication you can
see this.
ac921801-4673-4330-a447-ea53c9488427/3469-0
00:13:34.596 --> 00:13:38.251
You can clearly see the lower
frequency behavior of the wave
ac921801-4673-4330-a447-ea53c9488427/3469-1
00:13:38.251 --> 00:13:41.845
field in this area, which is
maybe due to the magma chamber
ac921801-4673-4330-a447-ea53c9488427/3469-2
00:13:41.845 --> 00:13:45.739
the that's part of the fiber is
in that area so, but it is still
ac921801-4673-4330-a447-ea53c9488427/3469-3
00:13:45.739 --> 00:13:49.274
undergoing and we don't know
exactly how to perform there,
ac921801-4673-4330-a447-ea53c9488427/3469-4
00:13:49.274 --> 00:13:52.509
but for this specific study,
we're gonna try to use a
ac921801-4673-4330-a447-ea53c9488427/3469-5
00:13:52.509 --> 00:13:54.366
seismicity, natural seismicity.
ac921801-4673-4330-a447-ea53c9488427/3497-0
00:13:54.406 --> 00:13:57.265
This is the seismicity of
actually like just the one year
ac921801-4673-4330-a447-ea53c9488427/3497-1
00:13:57.265 --> 00:13:59.976
we have more than 6000 local and
regional earthquakes.
ac921801-4673-4330-a447-ea53c9488427/3508-0
00:13:59.986 --> 00:14:02.376
You can see it's a fairly decent
uh.
ac921801-4673-4330-a447-ea53c9488427/3606-0
00:14:02.686 --> 00:14:06.502
As you tell distribution of
seismicity and that's actually
ac921801-4673-4330-a447-ea53c9488427/3606-1
00:14:06.502 --> 00:14:10.577
what help us expand a little bit
to see resolution or at least
ac921801-4673-4330-a447-ea53c9488427/3606-2
00:14:10.577 --> 00:14:14.586
the sensitivity, the hard part
that when I joined Caltech was
ac921801-4673-4330-a447-ea53c9488427/3606-3
00:14:14.586 --> 00:14:18.402
actually have a way to pink
travel time from dust data and
ac921801-4673-4330-a447-ea53c9488427/3606-4
00:14:18.402 --> 00:14:22.283
trust me, I spend a lot of time
and doing and I you know we
ac921801-4673-4330-a447-ea53c9488427/3606-5
00:14:22.283 --> 00:14:26.098
discuss a lot and then I was
lucky enough because we train
ac921801-4673-4330-a447-ea53c9488427/3606-6
00:14:26.098 --> 00:14:30.238
Zoo joined Caltech and he's the
developer of his net dot of his
ac921801-4673-4330-a447-ea53c9488427/3606-7
00:14:30.238 --> 00:14:30.496
net.
ac921801-4673-4330-a447-ea53c9488427/3631-0
00:14:30.506 --> 00:14:35.473
As you maybe know of you know
and we together we were able to
ac921801-4673-4330-a447-ea53c9488427/3631-1
00:14:35.473 --> 00:14:38.436
actually generate a new set of
tool.
ac921801-4673-4330-a447-ea53c9488427/3638-0
00:14:38.746 --> 00:14:40.696
Basically fishnet does is
actually published.
ac921801-4673-4330-a447-ea53c9488427/3646-0
00:14:40.706 --> 00:14:41.786
It's not under review.
ac921801-4673-4330-a447-ea53c9488427/3664-0
00:14:41.946 --> 00:14:45.086
It should have updated this, but
Vick is pretty much the same
ac921801-4673-4330-a447-ea53c9488427/3664-1
00:14:45.086 --> 00:14:45.896
process you get.
ac921801-4673-4330-a447-ea53c9488427/3675-0
00:14:46.196 --> 00:14:48.036
You know the DOS data on one
end.
ac921801-4673-4330-a447-ea53c9488427/3708-0
00:14:48.106 --> 00:14:51.474
You go through a machine
learning method and you get the
ac921801-4673-4330-a447-ea53c9488427/3708-1
00:14:51.474 --> 00:14:55.137
key phases for PNS weights and I
will tell you how and I will
ac921801-4673-4330-a447-ea53c9488427/3708-2
00:14:55.137 --> 00:14:56.436
show you how it works.
ac921801-4673-4330-a447-ea53c9488427/3746-0
00:14:56.886 --> 00:15:00.613
The tricky part was to actually
have, you know, labeled data
ac921801-4673-4330-a447-ea53c9488427/3746-1
00:15:00.613 --> 00:15:04.524
that of course for DAS we don't
have like manual pigs from, you
ac921801-4673-4330-a447-ea53c9488427/3746-2
00:15:04.524 --> 00:15:08.006
know, many years of, you know,
effort from the different
ac921801-4673-4330-a447-ea53c9488427/3746-3
00:15:08.006 --> 00:15:08.556
networks.
ac921801-4673-4330-a447-ea53c9488427/3770-0
00:15:08.836 --> 00:15:13.378
And so we actually use phase net
on single channels to get the
ac921801-4673-4330-a447-ea53c9488427/3770-1
00:15:13.378 --> 00:15:17.126
first prediction of the phases
or the arrival time.
ac921801-4673-4330-a447-ea53c9488427/3859-0
00:15:17.376 --> 00:15:21.534
We clean up the labels, get a
little bit of machine learning
ac921801-4673-4330-a447-ea53c9488427/3859-1
00:15:21.534 --> 00:15:25.828
tricks like the documentation
training that they the phase net
ac921801-4673-4330-a447-ea53c9488427/3859-2
00:15:25.828 --> 00:15:30.259
does on this set of label, get a
model, reproject the earthquake
ac921801-4673-4330-a447-ea53c9488427/3859-3
00:15:30.259 --> 00:15:34.144
and go on for three times
actually and then you can find
ac921801-4673-4330-a447-ea53c9488427/3859-4
00:15:34.144 --> 00:15:38.438
all the details in the in the
paper and the other thing that I
ac921801-4673-4330-a447-ea53c9488427/3859-5
00:15:38.438 --> 00:15:42.664
want to show you is that like
how effective it is actually on
ac921801-4673-4330-a447-ea53c9488427/3859-6
00:15:42.664 --> 00:15:44.436
a good SNR data of course.
ac921801-4673-4330-a447-ea53c9488427/3870-0
00:15:44.496 --> 00:15:47.416
And these are very, very nice
and clean earthquakes.
ac921801-4673-4330-a447-ea53c9488427/3890-0
00:15:47.426 --> 00:15:50.970
You can see the red curves and
the blue curves on these two
ac921801-4673-4330-a447-ea53c9488427/3890-1
00:15:50.970 --> 00:15:52.506
events are actually faced.
ac921801-4673-4330-a447-ea53c9488427/3942-0
00:15:52.566 --> 00:15:56.870
Net dust, pig travel times and
there are very, very accurate
ac921801-4673-4330-a447-ea53c9488427/3942-1
00:15:56.870 --> 00:16:01.386
considering you know like these
are we were not included in the
ac921801-4673-4330-a447-ea53c9488427/3942-2
00:16:01.386 --> 00:16:05.831
training and even as we move to
other arrays at least for land
ac921801-4673-4330-a447-ea53c9488427/3942-3
00:16:05.831 --> 00:16:09.006
fibers we know this that it
works very well.
ac921801-4673-4330-a447-ea53c9488427/3953-0
00:16:09.016 --> 00:16:11.596
I even test this on a Iceland
fiber.
ac921801-4673-4330-a447-ea53c9488427/3975-0
00:16:11.606 --> 00:16:14.612
We have an instrument in Iceland
and it works decently well
ac921801-4673-4330-a447-ea53c9488427/3975-1
00:16:14.612 --> 00:16:17.316
considering that we never use
this data for training.
ac921801-4673-4330-a447-ea53c9488427/4045-0
00:16:18.576 --> 00:16:22.559
Now the question is, I come from
a background of imaging, as
ac921801-4673-4330-a447-ea53c9488427/4045-1
00:16:22.559 --> 00:16:26.608
Alicia said, and the idea is
that first was to try to do FWIW
ac921801-4673-4330-a447-ea53c9488427/4045-2
00:16:26.608 --> 00:16:30.656
full forming version, which we
found kind of crazy for now we
ac921801-4673-4330-a447-ea53c9488427/4045-3
00:16:30.656 --> 00:16:34.313
have ideas now, but at the time
it was kind of probably
ac921801-4673-4330-a447-ea53c9488427/4045-4
00:16:34.313 --> 00:16:38.296
impossible to invert the, you
know, every single wiggle that
ac921801-4673-4330-a447-ea53c9488427/4045-5
00:16:38.296 --> 00:16:39.406
you can see here.
ac921801-4673-4330-a447-ea53c9488427/4063-0
00:16:39.506 --> 00:16:43.226
So we back down and go went to
travel time tomography.
ac921801-4673-4330-a447-ea53c9488427/4081-0
00:16:43.646 --> 00:16:46.856
And as I start reading, there
are a lot of methods.
ac921801-4673-4330-a447-ea53c9488427/4098-0
00:16:46.866 --> 00:16:50.011
For instance, Tomo did is one of
the very, very well established
ac921801-4673-4330-a447-ea53c9488427/4098-1
00:16:50.011 --> 00:16:51.656
method for performing
tomography.
ac921801-4673-4330-a447-ea53c9488427/4157-0
00:16:51.966 --> 00:16:55.320
The issue with that is is not
technically in a sense, it's
ac921801-4673-4330-a447-ea53c9488427/4157-1
00:16:55.320 --> 00:16:58.446
just the fact that in this
methodology they invert the
ac921801-4673-4330-a447-ea53c9488427/4157-2
00:16:58.446 --> 00:17:01.970
matrices even if they're sparse,
they're still very large and
ac921801-4673-4330-a447-ea53c9488427/4157-3
00:17:01.970 --> 00:17:05.096
just to give you a sense, like
it's done with a double
ac921801-4673-4330-a447-ea53c9488427/4157-4
00:17:05.096 --> 00:17:06.176
different approach.
ac921801-4673-4330-a447-ea53c9488427/4185-0
00:17:06.346 --> 00:17:10.374
But the common size of the data
set that have been treated with,
ac921801-4673-4330-a447-ea53c9488427/4185-1
00:17:10.374 --> 00:17:13.906
but this method is usually like,
you know, 100,000 pics.
ac921801-4673-4330-a447-ea53c9488427/4243-0
00:17:14.296 --> 00:17:17.556
But now we've does, even with
just six months of data, we get
ac921801-4673-4330-a447-ea53c9488427/4243-1
00:17:17.556 --> 00:17:20.921
the the like a billion pigs, and
you can imagine when you start
ac921801-4673-4330-a447-ea53c9488427/4243-2
00:17:20.921 --> 00:17:24.023
looking at actually double
difference you get the billions
ac921801-4673-4330-a447-ea53c9488427/4243-3
00:17:24.023 --> 00:17:27.440
of, you know, a lot of hundreds
of billions of travel time peaks
ac921801-4673-4330-a447-ea53c9488427/4243-4
00:17:27.440 --> 00:17:27.966
to invert.
ac921801-4673-4330-a447-ea53c9488427/4281-0
00:17:28.126 --> 00:17:31.845
These matrices will become huge
and that's the reason why we
ac921801-4673-4330-a447-ea53c9488427/4281-1
00:17:31.845 --> 00:17:35.625
decided to actually to use a an
adjoint state method approach
ac921801-4673-4330-a447-ea53c9488427/4281-2
00:17:35.625 --> 00:17:38.246
based on the economic tomography
equation.
ac921801-4673-4330-a447-ea53c9488427/4391-0
00:17:38.256 --> 00:17:41.870
This is just the economic
equation that given a velocity
ac921801-4673-4330-a447-ea53c9488427/4391-1
00:17:41.870 --> 00:17:45.864
field and a source location, we
can travel basically model the
ac921801-4673-4330-a447-ea53c9488427/4391-2
00:17:45.864 --> 00:17:50.048
travel time and uh what we do in
the methodology, we actually fix
ac921801-4673-4330-a447-ea53c9488427/4391-3
00:17:50.048 --> 00:17:53.915
the velocity and relocate the
events given a velocity field,
ac921801-4673-4330-a447-ea53c9488427/4391-4
00:17:53.915 --> 00:17:57.401
get the location, fix the
location into tomography and
ac921801-4673-4330-a447-ea53c9488427/4391-5
00:17:57.401 --> 00:18:01.459
it's specifically like I'm happy
to take question later, but we
ac921801-4673-4330-a447-ea53c9488427/4391-6
00:18:01.459 --> 00:18:05.579
for the location we actually use
seismic stations of the network
ac921801-4673-4330-a447-ea53c9488427/4391-7
00:18:05.579 --> 00:18:09.446
in that area because we have a
better azimuthal coverage for
ac921801-4673-4330-a447-ea53c9488427/4391-8
00:18:09.446 --> 00:18:12.806
the events and for the
tomography, we only use dots.
ac921801-4673-4330-a447-ea53c9488427/4412-0
00:18:13.136 --> 00:18:18.080
So and VP and VS are inverted
independently, so there is not
ac921801-4673-4330-a447-ea53c9488427/4412-1
00:18:18.080 --> 00:18:19.376
joint inversion.
ac921801-4673-4330-a447-ea53c9488427/4448-0
00:18:19.386 --> 00:18:23.726
So whatever you see in the VP
comes from only PvP or P way
ac921801-4673-4330-a447-ea53c9488427/4448-1
00:18:23.726 --> 00:18:28.065
travel time and whatever it
comes from the VSS is from the
ac921801-4673-4330-a447-ea53c9488427/4448-2
00:18:28.065 --> 00:18:29.536
PS wave travel time.
ac921801-4673-4330-a447-ea53c9488427/4461-0
00:18:29.546 --> 00:18:32.796
So, so the VBS ratio is kind of
unbiased.
ac921801-4673-4330-a447-ea53c9488427/4470-0
00:18:32.806 --> 00:18:34.726
If you make or, it'll be less
biased.
ac921801-4673-4330-a447-ea53c9488427/4482-0
00:18:35.556 --> 00:18:37.286
Let's have a look at the
results.
ac921801-4673-4330-a447-ea53c9488427/4490-0
00:18:37.416 --> 00:18:39.406
That is probably the most
interesting part.
ac921801-4673-4330-a447-ea53c9488427/4517-0
00:18:39.586 --> 00:18:43.614
On the left you can see the
perturbation with respect to 1
ac921801-4673-4330-a447-ea53c9488427/4517-1
00:18:43.614 --> 00:18:47.779
dev velocity model of the MVP
and on the on the right the VS
ac921801-4673-4330-a447-ea53c9488427/4517-2
00:18:47.779 --> 00:18:48.666
perturbation.
ac921801-4673-4330-a447-ea53c9488427/4541-0
00:18:48.736 --> 00:18:53.081
So what you can see red or more
red colors means you know lower
ac921801-4673-4330-a447-ea53c9488427/4541-1
00:18:53.081 --> 00:18:56.136
velocities and blue means higher
velocities.
ac921801-4673-4330-a447-ea53c9488427/4553-0
00:18:56.146 --> 00:19:00.226
You can clearly see the anomaly
in the Long Valley caldera.
ac921801-4673-4330-a447-ea53c9488427/4560-0
00:19:00.236 --> 00:19:01.646
This is a very shallow anomaly.
ac921801-4673-4330-a447-ea53c9488427/4576-0
00:19:01.656 --> 00:19:05.403
It's a 1 kilometer above the sea
level, 1 kilometer below the
ac921801-4673-4330-a447-ea53c9488427/4576-1
00:19:05.403 --> 00:19:05.886
surface.
ac921801-4673-4330-a447-ea53c9488427/4611-0
00:19:06.046 --> 00:19:09.136
Television is around 2
kilometers in the caldera,
ac921801-4673-4330-a447-ea53c9488427/4611-1
00:19:09.136 --> 00:19:13.090
approximately, and when we run
our tomography, you can see, you
ac921801-4673-4330-a447-ea53c9488427/4611-2
00:19:13.090 --> 00:19:16.056
know, things change quite a bit
as you can see.
ac921801-4673-4330-a447-ea53c9488427/4643-0
00:19:16.166 --> 00:19:19.789
First of all that you have this
very, very true, strong low
ac921801-4673-4330-a447-ea53c9488427/4643-1
00:19:19.789 --> 00:19:23.654
velocity anomaly for both VP and
BS and it will come later in a
ac921801-4673-4330-a447-ea53c9488427/4643-2
00:19:23.654 --> 00:19:24.076
second.
ac921801-4673-4330-a447-ea53c9488427/4673-0
00:19:24.486 --> 00:19:28.226
But the most interesting thing,
and I remember when I got the
ac921801-4673-4330-a447-ea53c9488427/4673-1
00:19:28.226 --> 00:19:31.785
preliminary result on this, we
saw this anomaly underneath
ac921801-4673-4330-a447-ea53c9488427/4673-2
00:19:31.785 --> 00:19:33.956
monologue and I didn't even
notice.
ac921801-4673-4330-a447-ea53c9488427/4680-0
00:19:33.966 --> 00:19:34.656
Don't, want said.
ac921801-4673-4330-a447-ea53c9488427/4712-0
00:19:34.666 --> 00:19:37.710
I think that's monologue and we
were super excited because we
ac921801-4673-4330-a447-ea53c9488427/4712-1
00:19:37.710 --> 00:19:40.901
thought, OK, it's cannot be just
a coincidence that thing and it
ac921801-4673-4330-a447-ea53c9488427/4712-2
00:19:40.901 --> 00:19:42.226
will come back in a second.
ac921801-4673-4330-a447-ea53c9488427/4765-0
00:19:42.456 --> 00:19:46.136
But the most interesting thing
is the fact that, as I said
ac921801-4673-4330-a447-ea53c9488427/4765-1
00:19:46.136 --> 00:19:49.941
there, this is the volcanism
migrated in along this NS trend
ac921801-4673-4330-a447-ea53c9488427/4765-2
00:19:49.941 --> 00:19:54.057
along the mono in Ukraine or and
there is actually like some kind
ac921801-4673-4330-a447-ea53c9488427/4765-3
00:19:54.057 --> 00:19:56.926
of small basin in this area
along this trend.
ac921801-4673-4330-a447-ea53c9488427/4791-0
00:19:56.936 --> 00:20:00.581
So it's kind of consistent what
with the surface expression of
ac921801-4673-4330-a447-ea53c9488427/4791-1
00:20:00.581 --> 00:20:01.796
this volcanic system.
ac921801-4673-4330-a447-ea53c9488427/4824-0
00:20:02.676 --> 00:20:06.427
Even more interesting, I think
when we look at the VPS ratio
ac921801-4673-4330-a447-ea53c9488427/4824-1
00:20:06.427 --> 00:20:10.054
for this specific area, it's a
small area here in the Long
ac921801-4673-4330-a447-ea53c9488427/4824-2
00:20:10.054 --> 00:20:10.976
Valley caldera.
ac921801-4673-4330-a447-ea53c9488427/4861-0
00:20:11.256 --> 00:20:14.707
I got the actually the
resistivity model from Jared
ac921801-4673-4330-a447-ea53c9488427/4861-1
00:20:14.707 --> 00:20:18.889
Peacock from his publication and
the interesting thing is that
ac921801-4673-4330-a447-ea53c9488427/4861-2
00:20:18.889 --> 00:20:21.676
the VPS Anomalies High VPS are
anomalies.
ac921801-4673-4330-a447-ea53c9488427/4958-0
00:20:21.836 --> 00:20:25.997
They actually correlate very
well with this high resistivity
ac921801-4673-4330-a447-ea53c9488427/4958-1
00:20:25.997 --> 00:20:29.885
and rim of low resistivity,
which we think actually it's
ac921801-4673-4330-a447-ea53c9488427/4958-2
00:20:29.885 --> 00:20:33.909
probably just driven by the
fluid or the alteration due to
ac921801-4673-4330-a447-ea53c9488427/4958-3
00:20:33.909 --> 00:20:37.933
hot geothermal fluid that bake
it the the rock there, it's
ac921801-4673-4330-a447-ea53c9488427/4958-4
00:20:37.933 --> 00:20:42.094
probably like I don't know if
it's full of fluid, but it the
ac921801-4673-4330-a447-ea53c9488427/4958-5
00:20:42.094 --> 00:20:46.391
for sure there is some kind of
and you know geological feature
ac921801-4673-4330-a447-ea53c9488427/4958-6
00:20:46.391 --> 00:20:50.688
there any correspond very well
with the geothermal Hot Springs
ac921801-4673-4330-a447-ea53c9488427/4958-7
00:20:50.688 --> 00:20:51.506
in the area.
ac921801-4673-4330-a447-ea53c9488427/5028-0
00:20:51.576 --> 00:20:55.800
So it was really nice to see
this correlation between the two
ac921801-4673-4330-a447-ea53c9488427/5028-1
00:20:55.800 --> 00:21:00.160
that are completely independent
in terms of just before we look
ac921801-4673-4330-a447-ea53c9488427/5028-2
00:21:00.160 --> 00:21:04.452
at a little bit deeper in the
model, we I tested just I got an
ac921801-4673-4330-a447-ea53c9488427/5028-3
00:21:04.452 --> 00:21:08.540
earthquake that was relocated,
but not using the tomography
ac921801-4673-4330-a447-ea53c9488427/5028-4
00:21:08.540 --> 00:21:12.559
just to get a sense how much
improvement will get from the
ac921801-4673-4330-a447-ea53c9488427/5028-5
00:21:12.559 --> 00:21:14.126
travel time tomography.
ac921801-4673-4330-a447-ea53c9488427/5062-0
00:21:14.136 --> 00:21:18.271
You can see the dashed lines are
the P, wave and waves predicted
ac921801-4673-4330-a447-ea53c9488427/5062-1
00:21:18.271 --> 00:21:22.343
from the initial model and after
tomography you can see that it
ac921801-4673-4330-a447-ea53c9488427/5062-2
00:21:22.343 --> 00:21:24.696
matches very well our observed
data.
ac921801-4673-4330-a447-ea53c9488427/5080-0
00:21:26.246 --> 00:21:31.244
Then let's have a look at few
profiles and let's start with
ac921801-4673-4330-a447-ea53c9488427/5080-1
00:21:31.244 --> 00:21:32.576
this NS transit.
ac921801-4673-4330-a447-ea53c9488427/5098-0
00:21:32.586 --> 00:21:38.276
So a A prime and here are like
the VP MVS Transact along.
ac921801-4673-4330-a447-ea53c9488427/5118-0
00:21:38.286 --> 00:21:43.397
That along that line about and
on the top is the VP and then
ac921801-4673-4330-a447-ea53c9488427/5118-1
00:21:43.397 --> 00:21:45.156
the bottom is the VS.
ac921801-4673-4330-a447-ea53c9488427/5128-0
00:21:45.406 --> 00:21:47.496
This is South and this is north.
ac921801-4673-4330-a447-ea53c9488427/5130-0
00:21:47.586 --> 00:21:48.136
OK.
ac921801-4673-4330-a447-ea53c9488427/5150-0
00:21:48.786 --> 00:21:53.472
And you can clearly see this low
velocity anomaly in associated
ac921801-4673-4330-a447-ea53c9488427/5150-1
00:21:53.472 --> 00:21:55.156
with the magma chamber.
ac921801-4673-4330-a447-ea53c9488427/5164-0
00:21:55.246 --> 00:21:59.656
But the big thing here is that
you can just from these images.
ac921801-4673-4330-a447-ea53c9488427/5213-0
00:21:59.666 --> 00:22:03.209
You would say there is some kind
of conduit connecting the
ac921801-4673-4330-a447-ea53c9488427/5213-1
00:22:03.209 --> 00:22:06.811
shallow surface with the big
magma chamber, and when we run
ac921801-4673-4330-a447-ea53c9488427/5213-2
00:22:06.811 --> 00:22:10.593
our tomography, actually we run
a lot of different travel time
ac921801-4673-4330-a447-ea53c9488427/5213-3
00:22:10.593 --> 00:22:14.376
tomography, different events and
we always see pretty much the
ac921801-4673-4330-a447-ea53c9488427/5213-4
00:22:14.376 --> 00:22:15.036
same story.
ac921801-4673-4330-a447-ea53c9488427/5232-0
00:22:15.406 --> 00:22:19.349
We can see the magma chamber,
but the biggest feature here is
ac921801-4673-4330-a447-ea53c9488427/5232-1
00:22:19.349 --> 00:22:20.176
this feature.
ac921801-4673-4330-a447-ea53c9488427/5270-0
00:22:20.186 --> 00:22:23.864
Low higher velocity feature that
is separating the shallow part
ac921801-4673-4330-a447-ea53c9488427/5270-1
00:22:23.864 --> 00:22:27.541
with the deeper magma chamber,
and that's actually what kind of
ac921801-4673-4330-a447-ea53c9488427/5270-2
00:22:27.541 --> 00:22:31.276
excite us and thought, OK, maybe
we found something interesting.
ac921801-4673-4330-a447-ea53c9488427/5282-0
00:22:31.286 --> 00:22:33.888
And the VPS ratio is gonna be
even more striking in my
ac921801-4673-4330-a447-ea53c9488427/5282-1
00:22:33.888 --> 00:22:34.266
opinion.
ac921801-4673-4330-a447-ea53c9488427/5320-0
00:22:35.216 --> 00:22:38.159
The other thing that is
interesting, you can see that
ac921801-4673-4330-a447-ea53c9488427/5320-1
00:22:38.159 --> 00:22:41.647
there is this small, you know,
bump that is a little bit higher
ac921801-4673-4330-a447-ea53c9488427/5320-2
00:22:41.647 --> 00:22:44.426
velocity in the middle of the
Long Valley caldera.
ac921801-4673-4330-a447-ea53c9488427/5342-0
00:22:44.596 --> 00:22:48.868
That's actually correspond where
the low value exploration well
ac921801-4673-4330-a447-ea53c9488427/5342-1
00:22:48.868 --> 00:22:52.406
was drilled and any correspond
to a low temperature.
ac921801-4673-4330-a447-ea53c9488427/5381-0
00:22:52.596 --> 00:22:56.740
And I had that discussion with
Emily Brodsky about this to try
ac921801-4673-4330-a447-ea53c9488427/5381-1
00:22:56.740 --> 00:23:00.752
to understand the correlation
between the geothermal and the
ac921801-4673-4330-a447-ea53c9488427/5381-2
00:23:00.752 --> 00:23:03.646
temperature profile with the
features here.
ac921801-4673-4330-a447-ea53c9488427/5408-0
00:23:03.716 --> 00:23:06.253
But at least like the
correspondence is kind of a
ac921801-4673-4330-a447-ea53c9488427/5408-1
00:23:06.253 --> 00:23:09.145
striking, the fact that, OK,
yeah, we have high velocity
ac921801-4673-4330-a447-ea53c9488427/5408-2
00:23:09.145 --> 00:23:10.616
material and low temperature.
ac921801-4673-4330-a447-ea53c9488427/5430-0
00:23:10.626 --> 00:23:13.664
So maybe there is a less
circulation and it cannot make
ac921801-4673-4330-a447-ea53c9488427/5430-1
00:23:13.664 --> 00:23:15.616
sense that there is no magma
there.
ac921801-4673-4330-a447-ea53c9488427/5440-0
00:23:15.626 --> 00:23:19.006
At least let's have a look a
little bit more.
ac921801-4673-4330-a447-ea53c9488427/5473-0
00:23:19.336 --> 00:23:23.698
The mono in your or creator,
especially like the monolake
ac921801-4673-4330-a447-ea53c9488427/5473-1
00:23:23.698 --> 00:23:28.360
because one day I was wondering
around the library at Caltech
ac921801-4673-4330-a447-ea53c9488427/5473-2
00:23:28.360 --> 00:23:32.496
and I found this reprint from a
very old studies from.
ac921801-4673-4330-a447-ea53c9488427/5523-0
00:23:33.066 --> 00:23:37.327
A compact and gravity and this
is actually the this profile C
ac921801-4673-4330-a447-ea53c9488427/5523-1
00:23:37.327 --> 00:23:41.726
prime where in the initial model
you don't see much and then in
ac921801-4673-4330-a447-ea53c9488427/5523-2
00:23:41.726 --> 00:23:46.124
the inverted model you can see
very strong low velocity anomaly
ac921801-4673-4330-a447-ea53c9488427/5523-3
00:23:46.124 --> 00:23:47.636
or close to monologue.
ac921801-4673-4330-a447-ea53c9488427/5564-0
00:23:48.046 --> 00:23:52.101
And if you look at this paper of
the gravity study, you can see
ac921801-4673-4330-a447-ea53c9488427/5564-1
00:23:52.101 --> 00:23:55.395
that actually like the
correspondence between their
ac921801-4673-4330-a447-ea53c9488427/5564-2
00:23:55.395 --> 00:23:59.513
velocity, their density model is
very, very close to what we see
ac921801-4673-4330-a447-ea53c9488427/5564-3
00:23:59.513 --> 00:24:01.096
in the tomographic image.
ac921801-4673-4330-a447-ea53c9488427/5579-0
00:24:01.106 --> 00:24:05.445
So it's just, but you know, an
interesting correlation between
ac921801-4673-4330-a447-ea53c9488427/5579-1
00:24:05.445 --> 00:24:05.996
the two.
ac921801-4673-4330-a447-ea53c9488427/5586-0
00:24:07.266 --> 00:24:07.816
Let's look.
ac921801-4673-4330-a447-ea53c9488427/5632-0
00:24:07.826 --> 00:24:12.358
Have a look at the West, East or
East West profiles before we
ac921801-4673-4330-a447-ea53c9488427/5632-1
00:24:12.358 --> 00:24:16.378
move to having a look at the
actually the entire cross
ac921801-4673-4330-a447-ea53c9488427/5632-2
00:24:16.378 --> 00:24:21.056
section throughout the system on
the left is the initial model,
ac921801-4673-4330-a447-ea53c9488427/5632-3
00:24:21.056 --> 00:24:23.176
the right the inverted model.
ac921801-4673-4330-a447-ea53c9488427/5637-0
00:24:23.406 --> 00:24:24.676
Pretty much the same story.
ac921801-4673-4330-a447-ea53c9488427/5655-0
00:24:24.686 --> 00:24:28.749
We have a fairly decent
separation between the shallow
ac921801-4673-4330-a447-ea53c9488427/5655-1
00:24:28.749 --> 00:24:30.596
part and the deeper part.
ac921801-4673-4330-a447-ea53c9488427/5682-0
00:24:30.606 --> 00:24:34.502
The shallow part we think it's
basically just the hydrothermal
ac921801-4673-4330-a447-ea53c9488427/5682-1
00:24:34.502 --> 00:24:38.274
system, plus some, you know,
little different lithologies at
ac921801-4673-4330-a447-ea53c9488427/5682-2
00:24:38.274 --> 00:24:39.016
the surface.
ac921801-4673-4330-a447-ea53c9488427/5707-0
00:24:39.166 --> 00:24:42.126
But there is this clear
separation that was not present
ac921801-4673-4330-a447-ea53c9488427/5707-1
00:24:42.126 --> 00:24:43.236
in the initial model.
ac921801-4673-4330-a447-ea53c9488427/5744-0
00:24:44.676 --> 00:24:48.139
And actually, if you happen to
go to Mama flakes at the top,
ac921801-4673-4330-a447-ea53c9488427/5744-1
00:24:48.139 --> 00:24:51.546
you will see the same movie,
because if this moving to some
ac921801-4673-4330-a447-ea53c9488427/5744-2
00:24:51.546 --> 00:24:54.782
people that they the top of this
area where they have an
ac921801-4673-4330-a447-ea53c9488427/5744-3
00:24:54.782 --> 00:24:55.406
exhibition.
ac921801-4673-4330-a447-ea53c9488427/5762-0
00:24:55.696 --> 00:24:58.648
But in this case, we're gonna
see they can just move it
ac921801-4673-4330-a447-ea53c9488427/5762-1
00:24:58.648 --> 00:25:00.176
throughout the entire system.
ac921801-4673-4330-a447-ea53c9488427/5798-0
00:25:00.186 --> 00:25:02.883
You can see the red line
indicates the current section
ac921801-4673-4330-a447-ea53c9488427/5798-1
00:25:02.883 --> 00:25:05.922
that we're seeing, and you can
see always like throughout the
ac921801-4673-4330-a447-ea53c9488427/5798-2
00:25:05.922 --> 00:25:07.246
entire Long Valley caldera.
ac921801-4673-4330-a447-ea53c9488427/5809-0
00:25:07.256 --> 00:25:11.246
You can see this nice separation
between magma chamber and the
ac921801-4673-4330-a447-ea53c9488427/5809-1
00:25:11.246 --> 00:25:12.006
bottom part.
ac921801-4673-4330-a447-ea53c9488427/5873-0
00:25:14.026 --> 00:25:19.626
And so PPVS ratio, as I said, I
think it's even more interesting
ac921801-4673-4330-a447-ea53c9488427/5873-1
00:25:19.626 --> 00:25:24.536
compared to other and in
particular like here we see the
ac921801-4673-4330-a447-ea53c9488427/5873-2
00:25:24.536 --> 00:25:30.049
again like the South N Transact,
this is the West East Transact
ac921801-4673-4330-a447-ea53c9488427/5873-3
00:25:30.049 --> 00:25:35.476
and red means very much like a
crustal rock VPS ratio of 1.74.
ac921801-4673-4330-a447-ea53c9488427/5913-0
00:25:35.846 --> 00:25:40.076
And the blue part is actually
like anything above 1.8, so
ac921801-4673-4330-a447-ea53c9488427/5913-1
00:25:40.076 --> 00:25:44.525
anything that could be either
related to fluids or magma and
ac921801-4673-4330-a447-ea53c9488427/5913-2
00:25:44.525 --> 00:25:47.806
in this case again the same
story as before.
ac921801-4673-4330-a447-ea53c9488427/5945-0
00:25:47.856 --> 00:25:51.739
You can see this big conduit
connecting the deeper part from
ac921801-4673-4330-a447-ea53c9488427/5945-1
00:25:51.739 --> 00:25:55.367
the shallow part and there is
not very clear correlation
ac921801-4673-4330-a447-ea53c9488427/5945-2
00:25:55.367 --> 00:25:57.786
between seismicity and the VPS
ratio.
ac921801-4673-4330-a447-ea53c9488427/6000-0
00:25:58.826 --> 00:26:03.006
When we run our thermography,
actually you can clearly see
ac921801-4673-4330-a447-ea53c9488427/6000-1
00:26:03.006 --> 00:26:06.974
that now this seismicity is
actually confined into this
ac921801-4673-4330-a447-ea53c9488427/6000-2
00:26:06.974 --> 00:26:10.871
normal or crustal rock,
seismicity, or like values VPS
ac921801-4673-4330-a447-ea53c9488427/6000-3
00:26:10.871 --> 00:26:15.547
ratio, and and also like you can
clearly see a separation between
ac921801-4673-4330-a447-ea53c9488427/6000-4
00:26:15.547 --> 00:26:17.176
the magma chamber here.
ac921801-4673-4330-a447-ea53c9488427/6005-0
00:26:17.186 --> 00:26:18.056
Adapt around.
ac921801-4673-4330-a447-ea53c9488427/6027-0
00:26:18.066 --> 00:26:22.219
You can see the top is around
7:50 kilometer depth and very
ac921801-4673-4330-a447-ea53c9488427/6027-1
00:26:22.219 --> 00:26:22.496
key.
ac921801-4673-4330-a447-ea53c9488427/6034-0
00:26:22.586 --> 00:26:24.996
The shallow part is completely
separated.
ac921801-4673-4330-a447-ea53c9488427/6052-0
00:26:25.146 --> 00:26:27.814
Of course, this doesn't mean
that there are not small
ac921801-4673-4330-a447-ea53c9488427/6052-1
00:26:27.814 --> 00:26:29.296
intrusion or things like that.
ac921801-4673-4330-a447-ea53c9488427/6057-0
00:26:29.306 --> 00:26:30.696
Very, very tiny Tykes.
ac921801-4673-4330-a447-ea53c9488427/6081-0
00:26:30.926 --> 00:26:35.674
But the at least there is not
like a big, big magma chamber
ac921801-4673-4330-a447-ea53c9488427/6081-1
00:26:35.674 --> 00:26:37.336
shallow in this case.
ac921801-4673-4330-a447-ea53c9488427/6136-0
00:26:38.026 --> 00:26:41.745
Another thing that it was
interesting, I noticed that a
ac921801-4673-4330-a447-ea53c9488427/6136-1
00:26:41.745 --> 00:26:45.929
lot of the seismicity actually
kind of stagnate around the the
ac921801-4673-4330-a447-ea53c9488427/6136-2
00:26:45.929 --> 00:26:49.383
area which is actually
corresponding very well with
ac921801-4673-4330-a447-ea53c9488427/6136-3
00:26:49.383 --> 00:26:53.633
some of the juridic source that
were inverted by other studies,
ac921801-4673-4330-a447-ea53c9488427/6136-4
00:26:53.633 --> 00:26:55.426
Judaic studies in the past.
ac921801-4673-4330-a447-ea53c9488427/6191-0
00:26:55.656 --> 00:26:58.980
So that's really like a nice
another correspondence to
ac921801-4673-4330-a447-ea53c9488427/6191-1
00:26:58.980 --> 00:27:02.848
validate because it really like
tomography is kind of an art if
ac921801-4673-4330-a447-ea53c9488427/6191-2
00:27:02.848 --> 00:27:06.656
if you may and whatever anomaly
you see, you need to make sure
ac921801-4673-4330-a447-ea53c9488427/6191-3
00:27:06.656 --> 00:27:09.436
that it's real before you can
clean anything.
ac921801-4673-4330-a447-ea53c9488427/6259-0
00:27:09.446 --> 00:27:12.807
Then I have in other studies
like there is this DVD
ac921801-4673-4330-a447-ea53c9488427/6259-1
00:27:12.807 --> 00:27:17.073
measurement and this other thing
and a lot of the feature that we
ac921801-4673-4330-a447-ea53c9488427/6259-2
00:27:17.073 --> 00:27:20.757
see as being seen by other
researcher with other studies
ac921801-4673-4330-a447-ea53c9488427/6259-3
00:27:20.757 --> 00:27:24.894
like the Long Valley Caldera has
has so rich of literature that
ac921801-4673-4330-a447-ea53c9488427/6259-4
00:27:24.894 --> 00:27:27.156
it's hard to actually navigate
it.
ac921801-4673-4330-a447-ea53c9488427/6262-0
00:27:27.266 --> 00:27:27.716
Yeah.
ac921801-4673-4330-a447-ea53c9488427/6273-0
00:27:27.806 --> 00:27:30.996
Yeah, you know, papers around
it.
ac921801-4673-4330-a447-ea53c9488427/6319-0
00:27:31.366 --> 00:27:34.922
But a lot of the feature were
kind of seen, but they were not
ac921801-4673-4330-a447-ea53c9488427/6319-1
00:27:34.922 --> 00:27:38.362
able to put it together and I
think that's really like made
ac921801-4673-4330-a447-ea53c9488427/6319-2
00:27:38.362 --> 00:27:41.803
everything fit nicely together
and that's actually like one
ac921801-4673-4330-a447-ea53c9488427/6319-3
00:27:41.803 --> 00:27:43.236
thing that I really like.
ac921801-4673-4330-a447-ea53c9488427/6346-0
00:27:43.286 --> 00:27:47.419
And before I conclude that I can
try even more, the point home is
ac921801-4673-4330-a447-ea53c9488427/6346-1
00:27:47.419 --> 00:27:51.176
the fact that, I mean, I come
from a background of geology.
ac921801-4673-4330-a447-ea53c9488427/6369-0
00:27:51.186 --> 00:27:54.024
I really like this kind of
images and even like sections
ac921801-4673-4330-a447-ea53c9488427/6369-1
00:27:54.024 --> 00:27:55.716
that I will show you in a
second.
ac921801-4673-4330-a447-ea53c9488427/6385-0
00:27:55.726 --> 00:27:58.446
But now, like we don't have to
draw this thing, we can see
ac921801-4673-4330-a447-ea53c9488427/6385-1
00:27:58.446 --> 00:27:58.676
them.
ac921801-4673-4330-a447-ea53c9488427/6402-0
00:27:59.026 --> 00:28:02.052
You know, we've, uh, real data
and actually managed them very,
ac921801-4673-4330-a447-ea53c9488427/6402-1
00:28:02.052 --> 00:28:02.676
very clearly.
ac921801-4673-4330-a447-ea53c9488427/6416-0
00:28:02.686 --> 00:28:06.056
I think that's actually what I
wanted to show in this image.
ac921801-4673-4330-a447-ea53c9488427/6499-0
00:28:06.826 --> 00:28:10.862
Let's give some pre conclusion
before I move to what we will
ac921801-4673-4330-a447-ea53c9488427/6499-1
00:28:10.862 --> 00:28:14.765
try next and hopefully soon
enough, but I hope I convinced
ac921801-4673-4330-a447-ea53c9488427/6499-2
00:28:14.765 --> 00:28:18.536
you and I showed you that
economy travel time tomography
ac921801-4673-4330-a447-ea53c9488427/6499-3
00:28:18.536 --> 00:28:22.638
combined with you know machine
learning tools for DOS and the
ac921801-4673-4330-a447-ea53c9488427/6499-4
00:28:22.638 --> 00:28:26.409
and accurate travel time
tomography actually seems to be
ac921801-4673-4330-a447-ea53c9488427/6499-5
00:28:26.409 --> 00:28:30.378
leading to new discoveries in
system that have been studied
ac921801-4673-4330-a447-ea53c9488427/6499-6
00:28:30.378 --> 00:28:32.826
for a long time and we're trying
to.
ac921801-4673-4330-a447-ea53c9488427/6611-0
00:28:32.896 --> 00:28:37.068
I even tried on the law and the
LA Basin, but it's that's a
ac921801-4673-4330-a447-ea53c9488427/6611-1
00:28:37.068 --> 00:28:41.032
different story and it works
fairly well the but in this
ac921801-4673-4330-a447-ea53c9488427/6611-2
00:28:41.032 --> 00:28:45.135
specific case, the tomographic
images they provide the new
ac921801-4673-4330-a447-ea53c9488427/6611-3
00:28:45.135 --> 00:28:49.446
evidence support in the long
standing debate about the second
ac921801-4673-4330-a447-ea53c9488427/6611-4
00:28:49.446 --> 00:28:53.966
boiling hypothesis and or fluid
driven, the arrest nature in the
ac921801-4673-4330-a447-ea53c9488427/6611-5
00:28:53.966 --> 00:28:58.346
Long Valley chamber and uh in
particularly actually like uh in
ac921801-4673-4330-a447-ea53c9488427/6611-6
00:28:58.346 --> 00:29:02.380
the paper we I took actually
this umm of geologic section
ac921801-4673-4330-a447-ea53c9488427/6611-7
00:29:02.380 --> 00:29:06.552
from this very nice paper by
hildred and I kind of tried to
ac921801-4673-4330-a447-ea53c9488427/6611-8
00:29:06.552 --> 00:29:10.376
use the VPS ratio plus this
section to make some kind.
ac921801-4673-4330-a447-ea53c9488427/6650-0
00:29:10.516 --> 00:29:14.664
Of summary feature of what's
going on in the Long Valley
ac921801-4673-4330-a447-ea53c9488427/6650-1
00:29:14.664 --> 00:29:19.175
Cadera in particular actually
like some of the, you know, the
ac921801-4673-4330-a447-ea53c9488427/6650-2
00:29:19.175 --> 00:29:23.468
the border between areas are
actually trimming from the my
ac921801-4673-4330-a447-ea53c9488427/6650-3
00:29:23.468 --> 00:29:23.686
TV.
ac921801-4673-4330-a447-ea53c9488427/6680-0
00:29:24.356 --> 00:29:28.092
So I use that to draw this and
that they geological section to
ac921801-4673-4330-a447-ea53c9488427/6680-1
00:29:28.092 --> 00:29:30.226
make it a little bit nicer
looking.
ac921801-4673-4330-a447-ea53c9488427/6683-0
00:29:30.236 --> 00:29:30.616
That's all.
ac921801-4673-4330-a447-ea53c9488427/6719-0
00:29:31.066 --> 00:29:33.765
And the other thing actually in
this area we say that there are
ac921801-4673-4330-a447-ea53c9488427/6719-1
00:29:33.765 --> 00:29:36.380
Hot Springs and indeed actually
like this, we know that there
ac921801-4673-4330-a447-ea53c9488427/6719-2
00:29:36.380 --> 00:29:37.856
are a lot of nice hot spins
there.
ac921801-4673-4330-a447-ea53c9488427/6737-0
00:29:38.186 --> 00:29:41.584
Not that you should take a bath
in those, but you know it's they
ac921801-4673-4330-a447-ea53c9488427/6737-1
00:29:41.584 --> 00:29:42.106
look nice.
ac921801-4673-4330-a447-ea53c9488427/6827-0
00:29:42.906 --> 00:29:46.818
Uh, and I feel like the main
point that I would like to say
ac921801-4673-4330-a447-ea53c9488427/6827-1
00:29:46.818 --> 00:29:50.469
and I will tell a little bit
more is the fact that Nova
ac921801-4673-4330-a447-ea53c9488427/6827-2
00:29:50.469 --> 00:29:54.185
recording tools with Mother
algorithm will actually like
ac921801-4673-4330-a447-ea53c9488427/6827-3
00:29:54.185 --> 00:29:58.032
give us like a new ground to
understand more our earth for
ac921801-4673-4330-a447-ea53c9488427/6827-4
00:29:58.032 --> 00:30:02.074
this specific actually thing we
are going to we are one thing
ac921801-4673-4330-a447-ea53c9488427/6827-5
00:30:02.074 --> 00:30:06.116
that I didn't do at all and I
hope to do in the future is the
ac921801-4673-4330-a447-ea53c9488427/6827-6
00:30:06.116 --> 00:30:07.876
analysis of the seismicity.
ac921801-4673-4330-a447-ea53c9488427/6846-0
00:30:08.226 --> 00:30:12.890
There are some lines that are
actually coming out out of the
ac921801-4673-4330-a447-ea53c9488427/6846-1
00:30:12.890 --> 00:30:15.336
relocation like this nice trend.
ac921801-4673-4330-a447-ea53c9488427/6895-0
00:30:15.786 --> 00:30:19.936
And one thing that I actually
was interesting as you many of
ac921801-4673-4330-a447-ea53c9488427/6895-1
00:30:19.936 --> 00:30:24.017
you know in a memo of Montana
has in the past happened that
ac921801-4673-4330-a447-ea53c9488427/6895-2
00:30:24.017 --> 00:30:28.438
they released a lot of CO2 from
the ground and kill a lot of the
ac921801-4673-4330-a447-ea53c9488427/6895-3
00:30:28.438 --> 00:30:28.846
trees.
ac921801-4673-4330-a447-ea53c9488427/6956-0
00:30:28.856 --> 00:30:33.126
And I heard even people and
Alicia actually published a very
ac921801-4673-4330-a447-ea53c9488427/6956-1
00:30:33.126 --> 00:30:37.396
interesting study where she
relocated some events over time,
ac921801-4673-4330-a447-ea53c9488427/6956-2
00:30:37.396 --> 00:30:41.176
and she was able to actually
find a trend of the this
ac921801-4673-4330-a447-ea53c9488427/6956-3
00:30:41.176 --> 00:30:45.656
seismicity showing that there is
a clear upgoing trend from the
ac921801-4673-4330-a447-ea53c9488427/6956-4
00:30:45.656 --> 00:30:49.506
ball deep part of the system to
the very shallow part.
ac921801-4673-4330-a447-ea53c9488427/6995-0
00:30:50.036 --> 00:30:54.607
And one thing I she sent me the
catalog and I plotted it on my
ac921801-4673-4330-a447-ea53c9488427/6995-1
00:30:54.607 --> 00:30:58.307
VPS ratio and one thing and
again like there is no
ac921801-4673-4330-a447-ea53c9488427/6995-2
00:30:58.307 --> 00:31:01.716
relocation, I just put the
catalog data there.
ac921801-4673-4330-a447-ea53c9488427/7009-0
00:31:01.806 --> 00:31:03.896
One thing that is interesting to
me is that there is a.
ac921801-4673-4330-a447-ea53c9488427/7069-0
00:31:03.946 --> 00:31:07.351
Of course, this is kind of
arbitrary, but there is some
ac921801-4673-4330-a447-ea53c9488427/7069-1
00:31:07.351 --> 00:31:11.060
kind of barrier here that it
kind of locks the seismicity in
ac921801-4673-4330-a447-ea53c9488427/7069-2
00:31:11.060 --> 00:31:14.283
this area, and then you have
this very nice trend of
ac921801-4673-4330-a447-ea53c9488427/7069-3
00:31:14.283 --> 00:31:18.114
earthquakes that are probably
driven by some preexisting fault
ac921801-4673-4330-a447-ea53c9488427/7069-4
00:31:18.114 --> 00:31:21.336
that are that are driving the
gas up to the surface.
ac921801-4673-4330-a447-ea53c9488427/7099-0
00:31:21.346 --> 00:31:25.064
And again like this is very
preliminary and we didn't want
ac921801-4673-4330-a447-ea53c9488427/7099-1
00:31:25.064 --> 00:31:28.782
to include this in the paper
because it was maybe too much
ac921801-4673-4330-a447-ea53c9488427/7099-2
00:31:28.782 --> 00:31:29.916
meat on the fired.
ac921801-4673-4330-a447-ea53c9488427/7119-0
00:31:29.956 --> 00:31:34.092
So, but it's kind of, I think 1
area that it should be analyzed
ac921801-4673-4330-a447-ea53c9488427/7119-1
00:31:34.092 --> 00:31:35.836
even further in the future.
ac921801-4673-4330-a447-ea53c9488427/7154-0
00:31:36.486 --> 00:31:41.420
The other thing is about trying
to image deeper this system and
ac921801-4673-4330-a447-ea53c9488427/7154-1
00:31:41.420 --> 00:31:46.431
as I said, like we got a fairly
decent resolution of the shallow
ac921801-4673-4330-a447-ea53c9488427/7154-2
00:31:46.431 --> 00:31:47.896
part of the system.
ac921801-4673-4330-a447-ea53c9488427/7169-0
00:31:48.346 --> 00:31:51.104
But you know, we have no
sensitivity for the be
ac921801-4673-4330-a447-ea53c9488427/7169-1
00:31:51.104 --> 00:31:51.736
perception.
ac921801-4673-4330-a447-ea53c9488427/7185-0
00:31:51.746 --> 00:31:55.433
So we don't know how this
basically plumes actually look
ac921801-4673-4330-a447-ea53c9488427/7185-1
00:31:55.433 --> 00:31:55.756
like.
ac921801-4673-4330-a447-ea53c9488427/7205-0
00:31:55.926 --> 00:32:01.423
From the Moho to the surface and
that's what we hope to do in the
ac921801-4673-4330-a447-ea53c9488427/7205-1
00:32:01.423 --> 00:32:02.006
future.
ac921801-4673-4330-a447-ea53c9488427/7224-0
00:32:02.016 --> 00:32:06.186
As I said, the array now it's a
200 kilometer in land.
ac921801-4673-4330-a447-ea53c9488427/7246-0
00:32:06.196 --> 00:32:10.178
This is actually one recording
for an an earthquake there, and
ac921801-4673-4330-a447-ea53c9488427/7246-1
00:32:10.178 --> 00:32:11.126
you can see it.
ac921801-4673-4330-a447-ea53c9488427/7304-0
00:32:11.136 --> 00:32:15.035
So the hope is that we have a
longer range, we are able to go
ac921801-4673-4330-a447-ea53c9488427/7304-1
00:32:15.035 --> 00:32:18.683
a little bit deeper and still
and try to image the deeper
ac921801-4673-4330-a447-ea53c9488427/7304-2
00:32:18.683 --> 00:32:22.770
structures and hopefully soon we
will have something and I guess
ac921801-4673-4330-a447-ea53c9488427/7304-3
00:32:22.770 --> 00:32:26.606
like a in the future, I will try
to explore the usage of WI.
ac921801-4673-4330-a447-ea53c9488427/7315-0
00:32:26.876 --> 00:32:28.926
But the point is that there we
are now.
ac921801-4673-4330-a447-ea53c9488427/7372-0
00:32:28.936 --> 00:32:32.327
We are at this current
tomographic standard kind of a
ac921801-4673-4330-a447-ea53c9488427/7372-1
00:32:32.327 --> 00:32:35.968
blurry picture and hopefully
we've the usage of new data,
ac921801-4673-4330-a447-ea53c9488427/7372-2
00:32:35.968 --> 00:32:39.547
HPC, of course and the modern
analysis tools, we can get
ac921801-4673-4330-a447-ea53c9488427/7372-3
00:32:39.547 --> 00:32:43.440
actually like to the right side
picture where we have a clear
ac921801-4673-4330-a447-ea53c9488427/7372-4
00:32:43.440 --> 00:32:45.386
understanding of these systems.
ac921801-4673-4330-a447-ea53c9488427/7399-0
00:32:46.436 --> 00:32:50.549
And of course, I thank opticians
for the support the telecom
ac921801-4673-4330-a447-ea53c9488427/7399-1
00:32:50.549 --> 00:32:54.662
company California Broadband
Cooperative for accessing their
ac921801-4673-4330-a447-ea53c9488427/7399-2
00:32:54.662 --> 00:32:55.066
fiber.
ac921801-4673-4330-a447-ea53c9488427/7407-0
00:32:55.296 --> 00:32:56.746
And of course, Margaret.
ac921801-4673-4330-a447-ea53c9488427/7423-0
00:32:56.756 --> 00:33:00.166
Jessica, Brianna and Daniel, 45,
to give this talk.
ac921801-4673-4330-a447-ea53c9488427/7431-0
00:33:00.616 --> 00:33:03.626
And with that, I'm happy to take
any questions.
ac921801-4673-4330-a447-ea53c9488427/7435-0
00:33:12.586 --> 00:33:12.956
OK.
ac921801-4673-4330-a447-ea53c9488427/7444-0
00:33:12.966 --> 00:33:15.136
Thank you very much for a great
talk.
ac921801-4673-4330-a447-ea53c9488427/7463-0
00:33:15.366 --> 00:33:19.656
We will start with any questions
in the Yosemite room here.
ac921801-4673-4330-a447-ea53c9488427/7494-0
00:33:19.786 --> 00:33:23.607
If people online have questions,
you can either put them in the
ac921801-4673-4330-a447-ea53c9488427/7467-0
00:33:20.246 --> 00:33:20.576
That's good.
ac921801-4673-4330-a447-ea53c9488427/7494-1
00:33:23.607 --> 00:33:27.487
chat or you can raise your hand
and then I'll take them and turn
ac921801-4673-4330-a447-ea53c9488427/7494-2
00:33:27.487 --> 00:33:29.516
and people can ask them
directly.
ac921801-4673-4330-a447-ea53c9488427/7501-0
00:33:32.836 --> 00:33:34.036
Any questions on this?
ac921801-4673-4330-a447-ea53c9488427/7504-0
00:33:34.046 --> 00:33:35.296
And then go ahead.
ac921801-4673-4330-a447-ea53c9488427/7534-0
00:33:35.546 --> 00:33:39.951
But I'm not a size smaller just
but I I was thinking a little
ac921801-4673-4330-a447-ea53c9488427/7534-1
00:33:39.951 --> 00:33:44.355
bit about the motivation you
started with, which is different
ac921801-4673-4330-a447-ea53c9488427/7534-2
00:33:44.355 --> 00:33:45.136
call there.
ac921801-4673-4330-a447-ea53c9488427/7545-0
00:33:47.466 --> 00:33:48.646
Events or eruption events?
ac921801-4673-4330-a447-ea53c9488427/7553-0
00:33:49.496 --> 00:33:52.066
Uh, just the tomography.
ac921801-4673-4330-a447-ea53c9488427/7581-0
00:33:52.076 --> 00:33:56.043
I mean, trophy helps us
understand the structure and you
ac921801-4673-4330-a447-ea53c9488427/7581-1
00:33:56.043 --> 00:33:59.801
pointed in a couple of places,
maybe briefly to fluid
ac921801-4673-4330-a447-ea53c9488427/7581-2
00:33:59.801 --> 00:34:00.706
accumulation.
ac921801-4673-4330-a447-ea53c9488427/7590-0
00:34:01.216 --> 00:34:03.716
Do you think the new data helps
us understand?
ac921801-4673-4330-a447-ea53c9488427/7638-0
00:34:04.336 --> 00:34:09.097
Umm, that evolution of the
caldera a little more are we are
ac921801-4673-4330-a447-ea53c9488427/7638-1
00:34:09.097 --> 00:34:14.016
we getting closer to eruption or
are we do we not have enough
ac921801-4673-4330-a447-ea53c9488427/7638-2
00:34:14.016 --> 00:34:18.300
historical data yet from the
chemotherapy to make any
ac921801-4673-4330-a447-ea53c9488427/7638-3
00:34:18.300 --> 00:34:19.966
conclusions based on?
ac921801-4673-4330-a447-ea53c9488427/7647-0
00:34:21.386 --> 00:34:24.456
But for the Long Valley caldera,
you mean specifically?
ac921801-4673-4330-a447-ea53c9488427/7653-0
00:34:23.686 --> 00:34:23.826
Yes.
ac921801-4673-4330-a447-ea53c9488427/7650-0
00:34:24.606 --> 00:34:25.256
OK.
ac921801-4673-4330-a447-ea53c9488427/7714-0
00:34:25.346 --> 00:34:29.400
That that's a I guess like for
me at least, the way I read the
ac921801-4673-4330-a447-ea53c9488427/7714-1
00:34:29.400 --> 00:34:32.874
tomographic images that we
obtained is just A at this
ac921801-4673-4330-a447-ea53c9488427/7714-2
00:34:32.874 --> 00:34:36.927
stage, it's kind of maybe there
are like small intrusions that
ac921801-4673-4330-a447-ea53c9488427/7714-3
00:34:36.927 --> 00:34:40.852
we can there are sub resolutions
and then maybe there is the
ac921801-4673-4330-a447-ea53c9488427/7714-4
00:34:40.852 --> 00:34:42.396
possibility of eruption.
ac921801-4673-4330-a447-ea53c9488427/7736-0
00:34:42.406 --> 00:34:46.805
I think it's unlikely but and
one thing that I think is
ac921801-4673-4330-a447-ea53c9488427/7736-1
00:34:46.805 --> 00:34:50.496
missing from you know the entire
DAS workflow.
ac921801-4673-4330-a447-ea53c9488427/7765-0
00:34:50.506 --> 00:34:54.498
It would be interesting to be
able to find a way to invert
ac921801-4673-4330-a447-ea53c9488427/7765-1
00:34:54.498 --> 00:34:58.896
moment tensors and get actually
a more grasp of what's going on.
ac921801-4673-4330-a447-ea53c9488427/7826-0
00:34:58.906 --> 00:35:03.313
That would give us a little bit
of better sense and then look at
ac921801-4673-4330-a447-ea53c9488427/7826-1
00:35:03.313 --> 00:35:07.381
the moment tensor in conjunction
with the images and try to
ac921801-4673-4330-a447-ea53c9488427/7826-2
00:35:07.381 --> 00:35:11.448
understand what they're, you
know, maybe you have some area
ac921801-4673-4330-a447-ea53c9488427/7826-3
00:35:11.448 --> 00:35:15.516
where you have intrusions or
just fluids and then but we we
ac921801-4673-4330-a447-ea53c9488427/7826-4
00:35:15.516 --> 00:35:17.346
can invert focal mechanism.
ac921801-4673-4330-a447-ea53c9488427/7865-0
00:35:17.356 --> 00:35:20.958
We publish a paper on that, but
I think one thing that would be
ac921801-4673-4330-a447-ea53c9488427/7865-1
00:35:20.958 --> 00:35:24.448
it's kind of missing from this
entire story to really put the
ac921801-4673-4330-a447-ea53c9488427/7865-2
00:35:24.448 --> 00:35:27.881
definitive answer on whether
there's gonna be an eruption or
ac921801-4673-4330-a447-ea53c9488427/7865-3
00:35:27.881 --> 00:35:28.106
not.
ac921801-4673-4330-a447-ea53c9488427/7877-0
00:35:28.116 --> 00:35:30.306
I think it's unlikely, at least
like a bigger option.
ac921801-4673-4330-a447-ea53c9488427/7902-0
00:35:30.316 --> 00:35:34.422
It's unlikely from you, although
if there was a big magma
ac921801-4673-4330-a447-ea53c9488427/7902-1
00:35:34.422 --> 00:35:38.386
chamber, we would have the image
very well, I think so.
ac921801-4673-4330-a447-ea53c9488427/7920-0
00:35:38.816 --> 00:35:42.044
Whether there's going to be
maybe a smaller option that's
ac921801-4673-4330-a447-ea53c9488427/7920-1
00:35:42.044 --> 00:35:43.046
it's hard to tell.
ac921801-4673-4330-a447-ea53c9488427/7947-0
00:35:43.056 --> 00:35:46.457
I think it's some resolution as
of now, and I hope maybe with
ac921801-4673-4330-a447-ea53c9488427/7947-1
00:35:46.457 --> 00:35:48.816
other method like FLW I could
answer that.
ac921801-4673-4330-a447-ea53c9488427/7963-0
00:35:49.026 --> 00:35:53.641
And so I guess like a the bigger
option is unlikely smaller
ac921801-4673-4330-a447-ea53c9488427/7963-1
00:35:53.641 --> 00:35:54.256
options.
ac921801-4673-4330-a447-ea53c9488427/8007-0
00:35:54.786 --> 00:35:57.855
We don't know the fact that in
the people we don't say like we
ac921801-4673-4330-a447-ea53c9488427/8007-1
00:35:57.855 --> 00:36:00.972
don't know that we like it's a
but a bigger option is unlikely,
ac921801-4673-4330-a447-ea53c9488427/8007-2
00:36:00.972 --> 00:36:03.846
which probably a lot of people
already kind of claim that.
ac921801-4673-4330-a447-ea53c9488427/8014-0
00:36:04.146 --> 00:36:06.886
But we'll see in the future.
ac921801-4673-4330-a447-ea53c9488427/8038-0
00:36:06.896 --> 00:36:09.836
I think like moment tensor
having the ability to invert
ac921801-4673-4330-a447-ea53c9488427/8038-1
00:36:09.836 --> 00:36:11.096
moment tensor with dust.
ac921801-4673-4330-a447-ea53c9488427/8056-0
00:36:11.316 --> 00:36:14.696
It would be really like a a big
step forward to try to
ac921801-4673-4330-a447-ea53c9488427/8056-1
00:36:14.696 --> 00:36:16.416
understand volcanic systems.
ac921801-4673-4330-a447-ea53c9488427/8098-0
00:36:16.676 --> 00:36:20.881
So you can imagine like in this
case we record the tons of
ac921801-4673-4330-a447-ea53c9488427/8098-1
00:36:20.881 --> 00:36:25.585
earthquakes and you have so many
channels that like we can see as
ac921801-4673-4330-a447-ea53c9488427/8098-2
00:36:25.585 --> 00:36:27.366
tiny as minus one events.
ac921801-4673-4330-a447-ea53c9488427/8105-0
00:36:27.376 --> 00:36:29.526
If they're close enough to the
five, so.
ac921801-4673-4330-a447-ea53c9488427/8111-0
00:36:31.666 --> 00:36:32.596
Oh yeah.
ac921801-4673-4330-a447-ea53c9488427/8116-0
00:36:32.646 --> 00:36:33.576
Great message. Thanks.
ac921801-4673-4330-a447-ea53c9488427/8117-0
00:36:34.366 --> 00:36:34.506
Yeah.
ac921801-4673-4330-a447-ea53c9488427/8122-0
00:36:38.506 --> 00:36:38.796
OK.
ac921801-4673-4330-a447-ea53c9488427/8132-0
00:36:38.806 --> 00:36:41.496
We have a couple questions in
the chat.
ac921801-4673-4330-a447-ea53c9488427/8153-0
00:36:41.646 --> 00:36:45.401
The first one is what is the
typical grid or cell size that
ac921801-4673-4330-a447-ea53c9488427/8153-1
00:36:45.401 --> 00:36:47.966
you are able to achieve with
these data?
ac921801-4673-4330-a447-ea53c9488427/8183-0
00:36:49.046 --> 00:36:53.187
OK, so for the modeling of the
travel time and inversion, I
ac921801-4673-4330-a447-ea53c9488427/8183-1
00:36:53.187 --> 00:36:57.603
actually use a 500 meters grid
for the finite difference finite
ac921801-4673-4330-a447-ea53c9488427/8183-2
00:36:57.603 --> 00:36:58.776
different method.
ac921801-4673-4330-a447-ea53c9488427/8230-0
00:36:58.846 --> 00:37:03.338
So it's just we resolve we solve
the travel time tomography or
ac921801-4673-4330-a447-ea53c9488427/8230-1
00:37:03.338 --> 00:37:07.260
like the travel economy
equation, we find a difference
ac921801-4673-4330-a447-ea53c9488427/8230-2
00:37:07.260 --> 00:37:11.396
and that's 500 meters, the
smallest anomaly that we could
ac921801-4673-4330-a447-ea53c9488427/8230-3
00:37:11.396 --> 00:37:11.966
resolve.
ac921801-4673-4330-a447-ea53c9488427/8250-0
00:37:11.976 --> 00:37:16.490
In this case I I we have been in
the supplemental material, it's
ac921801-4673-4330-a447-ea53c9488427/8250-1
00:37:16.490 --> 00:37:18.156
around 2 kilometer size.
ac921801-4673-4330-a447-ea53c9488427/8277-0
00:37:18.166 --> 00:37:23.056
Anything below that size, it's
very hard to image and even like
ac921801-4673-4330-a447-ea53c9488427/8277-1
00:37:23.056 --> 00:37:27.870
the two kilometer anomaly is the
absolute velocity is somewhat
ac921801-4673-4330-a447-ea53c9488427/8277-2
00:37:27.870 --> 00:37:29.016
underestimated.
ac921801-4673-4330-a447-ea53c9488427/8304-0
00:37:29.066 --> 00:37:32.493
If you guys have a low velocity,
but that's pretty much kind of a
ac921801-4673-4330-a447-ea53c9488427/8304-1
00:37:32.493 --> 00:37:35.036
resolution limit and pretty
depends on the area.
ac921801-4673-4330-a447-ea53c9488427/8361-0
00:37:35.446 --> 00:37:39.713
But in the study we only we
basically place but different
ac921801-4673-4330-a447-ea53c9488427/8361-1
00:37:39.713 --> 00:37:44.200
size of anomaly in the upper
crust to see whether we were we
ac921801-4673-4330-a447-ea53c9488427/8361-2
00:37:44.200 --> 00:37:48.540
would have been able to resolve
it or not and the smallest
ac921801-4673-4330-a447-ea53c9488427/8361-3
00:37:48.540 --> 00:37:53.248
anomaly they would resolve with
certainty was above 2 kilometer
ac921801-4673-4330-a447-ea53c9488427/8361-4
00:37:53.248 --> 00:37:53.836
in size.
ac921801-4673-4330-a447-ea53c9488427/8413-0
00:37:54.236 --> 00:37:57.334
That's pretty much the answer
that resolution, but the
ac921801-4673-4330-a447-ea53c9488427/8413-1
00:37:57.334 --> 00:38:00.826
inversion is done with a 500
meter grid in terms of numerical
ac921801-4673-4330-a447-ea53c9488427/8413-2
00:38:00.826 --> 00:38:04.262
and we have a Gaussian smoothing
for the gradient to kind of
ac921801-4673-4330-a447-ea53c9488427/8413-3
00:38:04.262 --> 00:38:07.416
regularize and not introduce
crazy artifacts during the
ac921801-4673-4330-a447-ea53c9488427/8413-4
00:38:07.416 --> 00:38:07.866
version.
ac921801-4673-4330-a447-ea53c9488427/8437-0
00:38:08.716 --> 00:38:12.688
But that's why everything is in
the paper and but and I can
ac921801-4673-4330-a447-ea53c9488427/8437-1
00:38:12.688 --> 00:38:15.666
answer more detailed questions
if necessary.
ac921801-4673-4330-a447-ea53c9488427/8440-0
00:38:19.596 --> 00:38:20.266
OK.
ac921801-4673-4330-a447-ea53c9488427/8449-0
00:38:20.276 --> 00:38:23.646
And another question from Walter
Mooney.
ac921801-4673-4330-a447-ea53c9488427/8456-0
00:38:23.656 --> 00:38:25.126
Thanks for the excellent talk.
ac921801-4673-4330-a447-ea53c9488427/8483-0
00:38:25.136 --> 00:38:30.180
Do you think that high V PVS
ratios, such as 1.85 are
ac921801-4673-4330-a447-ea53c9488427/8483-1
00:38:30.180 --> 00:38:33.636
commonly indicative of partial
melt?
ac921801-4673-4330-a447-ea53c9488427/8531-0
00:38:35.516 --> 00:38:39.943
Had that, and I think that goes
back to how to interpret these
ac921801-4673-4330-a447-ea53c9488427/8493-0
00:38:36.476 --> 00:38:36.716
True.
ac921801-4673-4330-a447-ea53c9488427/8531-1
00:38:39.943 --> 00:38:44.230
images, because even like the
geothermal part like the in in
ac921801-4673-4330-a447-ea53c9488427/8531-2
00:38:44.230 --> 00:38:48.446
in the shallow part we have
those five VPS ratio anomalies.
ac921801-4673-4330-a447-ea53c9488427/8560-0
00:38:48.636 --> 00:38:52.871
But we interpret as, not magma
or mad, but we and we say, is
ac921801-4673-4330-a447-ea53c9488427/8560-1
00:38:52.871 --> 00:38:55.926
actually like just water, fluids
or fluids.
ac921801-4673-4330-a447-ea53c9488427/8576-0
00:38:56.376 --> 00:39:00.028
How do we decide that is based
on previous knowledge right
ac921801-4673-4330-a447-ea53c9488427/8576-1
00:39:00.028 --> 00:39:01.266
that's been drilled?
ac921801-4673-4330-a447-ea53c9488427/8596-0
00:39:01.406 --> 00:39:04.836
So it's clear there are not
magma intrusions.
ac921801-4673-4330-a447-ea53c9488427/8627-0
00:39:05.236 --> 00:39:08.159
Otherwise, from just the
tomographic image we it's I
ac921801-4673-4330-a447-ea53c9488427/8627-1
00:39:08.159 --> 00:39:11.302
think it's hard like that's
really why it's not that the
ac921801-4673-4330-a447-ea53c9488427/8627-2
00:39:11.302 --> 00:39:13.176
tomography can answer
everything.
ac921801-4673-4330-a447-ea53c9488427/8648-0
00:39:13.186 --> 00:39:16.452
It gives you a sense, but you
still need some other data to
ac921801-4673-4330-a447-ea53c9488427/8648-1
00:39:16.452 --> 00:39:18.466
validate and understand the
anomaly.
ac921801-4673-4330-a447-ea53c9488427/8661-0
00:39:18.476 --> 00:39:21.156
So it's not that all the time
probably depends on the depth.
ac921801-4673-4330-a447-ea53c9488427/8697-0
00:39:21.166 --> 00:39:24.988
Like maybe if you see like a big
high PS ratio normally and you
ac921801-4673-4330-a447-ea53c9488427/8697-1
00:39:24.988 --> 00:39:28.571
know on the top there is a
volcano, that's probably the mag
ac921801-4673-4330-a447-ea53c9488427/8697-2
00:39:28.571 --> 00:39:29.466
machine, right?
ac921801-4673-4330-a447-ea53c9488427/8715-0
00:39:29.476 --> 00:39:33.105
It's kind of obvious, but that's
easy to say, but there's some
ac921801-4673-4330-a447-ea53c9488427/8715-1
00:39:33.105 --> 00:39:34.026
other anomalies.
ac921801-4673-4330-a447-ea53c9488427/8720-0
00:39:34.396 --> 00:39:35.346
It's harder.
ac921801-4673-4330-a447-ea53c9488427/8750-0
00:39:35.456 --> 00:39:38.607
You need all their data to
validate, in my opinion, and
ac921801-4673-4330-a447-ea53c9488427/8750-1
00:39:38.607 --> 00:39:41.702
tomography is just one of the
tools that we can use to
ac921801-4673-4330-a447-ea53c9488427/8750-2
00:39:41.702 --> 00:39:42.996
understand this system.
ac921801-4673-4330-a447-ea53c9488427/8790-0
00:39:43.006 --> 00:39:46.275
I think the Nice part of
Thermography gives you the
ac921801-4673-4330-a447-ea53c9488427/8790-1
00:39:46.275 --> 00:39:49.607
geometry and the relationship
between this this term
ac921801-4673-4330-a447-ea53c9488427/8790-2
00:39:49.607 --> 00:39:53.567
structures, which is something
that cannot give, for instance,
ac921801-4673-4330-a447-ea53c9488427/8790-3
00:39:53.567 --> 00:39:55.516
like even like gravity studies.
ac921801-4673-4330-a447-ea53c9488427/8846-0
00:39:55.526 --> 00:39:59.404
It's too low resolution to to be
view that, but again like it's
ac921801-4673-4330-a447-ea53c9488427/8846-1
00:39:59.404 --> 00:40:03.222
just tomography from tomography,
it's I think it's hard unless
ac921801-4673-4330-a447-ea53c9488427/8846-2
00:40:03.222 --> 00:40:06.857
you have previous knowledge
prior knowledge was fundamental
ac921801-4673-4330-a447-ea53c9488427/8846-3
00:40:06.857 --> 00:40:09.826
to make some of the claims we
made in the paper.
ac921801-4673-4330-a447-ea53c9488427/8863-0
00:40:09.936 --> 00:40:12.949
Without it, it would have been
very hard to to, you know,
ac921801-4673-4330-a447-ea53c9488427/8863-1
00:40:12.949 --> 00:40:14.196
corroborate what we see.
ac921801-4673-4330-a447-ea53c9488427/8880-0
00:40:16.856 --> 00:40:20.414
OK, so it looks like there is a
question from the folks in
ac921801-4673-4330-a447-ea53c9488427/8880-1
00:40:20.414 --> 00:40:20.956
Pasadena.
ac921801-4673-4330-a447-ea53c9488427/8892-0
00:40:21.046 --> 00:40:23.126
Would you like to unmute and ask
it?
ac921801-4673-4330-a447-ea53c9488427/8890-0
00:40:21.676 --> 00:40:21.896
Yep.
ac921801-4673-4330-a447-ea53c9488427/8895-0
00:40:24.256 --> 00:40:25.356
Yes. Yeah.
ac921801-4673-4330-a447-ea53c9488427/8902-0
00:40:27.216 --> 00:40:28.066
Yeah, I can repeat it.
ac921801-4673-4330-a447-ea53c9488427/8908-0
00:40:39.116 --> 00:40:41.206
Yes, I.
ac921801-4673-4330-a447-ea53c9488427/8918-0
00:40:49.706 --> 00:40:51.696
That that's a very, very good
point.
ac921801-4673-4330-a447-ea53c9488427/8933-0
00:40:51.706 --> 00:40:54.836
Like A and that goes back to
next steps, yes.
ac921801-4673-4330-a447-ea53c9488427/8963-0
00:40:54.846 --> 00:40:59.649
And the question was about like
trying to understand the size
ac921801-4673-4330-a447-ea53c9488427/8963-1
00:40:59.649 --> 00:41:04.296
mycity in why in the South rim
or the soft mod 4th and the?
ac921801-4673-4330-a447-ea53c9488427/8982-0
00:41:08.306 --> 00:41:10.596
There's some version the
question.
ac921801-4673-4330-a447-ea53c9488427/8974-0
00:41:09.056 --> 00:41:09.646
Yes.
ac921801-4673-4330-a447-ea53c9488427/8979-0
00:41:10.036 --> 00:41:10.746
Yeah, yeah, yeah.
ac921801-4673-4330-a447-ea53c9488427/8986-0
00:41:10.756 --> 00:41:11.546
I see this guy.
ac921801-4673-4330-a447-ea53c9488427/8996-0
00:41:12.706 --> 00:41:13.906
Uh, should I repeat the
question?
ac921801-4673-4330-a447-ea53c9488427/8995-0
00:41:13.306 --> 00:41:13.626
During.
ac921801-4673-4330-a447-ea53c9488427/9004-0
00:41:15.976 --> 00:41:16.636
Yes, please.
ac921801-4673-4330-a447-ea53c9488427/9041-0
00:41:17.276 --> 00:41:20.643
So the question was about if I
had look and analyze the
ac921801-4673-4330-a447-ea53c9488427/9041-1
00:41:20.643 --> 00:41:23.949
seismicity South of the Long
Valley Caldera and try to
ac921801-4673-4330-a447-ea53c9488427/9041-2
00:41:23.949 --> 00:41:27.195
understand what was going on
there, if I if I got the
ac921801-4673-4330-a447-ea53c9488427/9041-3
00:41:27.195 --> 00:41:27.736
question.
ac921801-4673-4330-a447-ea53c9488427/9143-0
00:41:34.586 --> 00:41:37.965
That said, with that I have a
look at that at all, so I really
ac921801-4673-4330-a447-ea53c9488427/9143-1
00:41:37.965 --> 00:41:41.183
just look at the long, but I
just it's separation, but it's
ac921801-4673-4330-a447-ea53c9488427/9143-2
00:41:41.183 --> 00:41:44.347
it's a good point actually like
try to understand, I think
ac921801-4673-4330-a447-ea53c9488427/9143-3
00:41:44.347 --> 00:41:47.243
that's something that is
completely missing from this
ac921801-4673-4330-a447-ea53c9488427/9143-4
00:41:47.243 --> 00:41:50.354
study is try to understand more
about this missing, maybe
ac921801-4673-4330-a447-ea53c9488427/9143-5
00:41:50.354 --> 00:41:53.786
actually like even look at the
historical data, redo relocation
ac921801-4673-4330-a447-ea53c9488427/9143-6
00:41:53.786 --> 00:41:57.272
maybe like a moment look at the
moment tensor and try to look at
ac921801-4673-4330-a447-ea53c9488427/9143-7
00:41:57.272 --> 00:42:00.436
the relationship between those
and this tomographic model.
ac921801-4673-4330-a447-ea53c9488427/9157-0
00:42:00.446 --> 00:42:02.728
It's true that the velocity has
changed a little bit, but
ac921801-4673-4330-a447-ea53c9488427/9157-1
00:42:02.728 --> 00:42:03.986
probably not that significantly.
ac921801-4673-4330-a447-ea53c9488427/9160-0
00:42:07.856 --> 00:42:09.016
Yeah. So.
ac921801-4673-4330-a447-ea53c9488427/9168-0
00:42:11.076 --> 00:42:12.086
Yeah, it would be interesting.
ac921801-4673-4330-a447-ea53c9488427/9197-0
00:42:12.096 --> 00:42:15.551
I haven't looked at all actually
like it's a I we should actually
ac921801-4673-4330-a447-ea53c9488427/9197-1
00:42:15.551 --> 00:42:18.430
like try to plot some cross
action and see how this is
ac921801-4673-4330-a447-ea53c9488427/9197-2
00:42:18.430 --> 00:42:19.006
unicity is.
ac921801-4673-4330-a447-ea53c9488427/9273-0
00:42:19.416 --> 00:42:23.015
Uh, we're especially because,
for instance, even this trend
ac921801-4673-4330-a447-ea53c9488427/9273-1
00:42:23.015 --> 00:42:26.373
that is far away like it was not
clear from the initial
ac921801-4673-4330-a447-ea53c9488427/9273-2
00:42:26.373 --> 00:42:29.971
tomography and and then after
relocation, it's really like,
ac921801-4673-4330-a447-ea53c9488427/9273-3
00:42:29.971 --> 00:42:33.630
you know, either it's a nice
correlation, but it it would be
ac921801-4673-4330-a447-ea53c9488427/9273-4
00:42:33.630 --> 00:42:37.288
interesting to do relocation
double dictionary location with
ac921801-4673-4330-a447-ea53c9488427/9273-5
00:42:37.288 --> 00:42:40.886
the 3D structure from the entire
data throughout the years.
ac921801-4673-4330-a447-ea53c9488427/9307-0
00:42:40.896 --> 00:42:44.175
And because we have data, I
think you know 50 years ago in
ac921801-4673-4330-a447-ea53c9488427/9307-1
00:42:44.175 --> 00:42:47.288
this year, so it would be
interesting to have a look at
ac921801-4673-4330-a447-ea53c9488427/9307-2
00:42:47.288 --> 00:42:49.066
that and try to understand more.
ac921801-4673-4330-a447-ea53c9488427/9329-0
00:42:49.076 --> 00:42:52.091
I think that's why you putting
then next step because it's
ac921801-4673-4330-a447-ea53c9488427/9329-1
00:42:52.091 --> 00:42:54.646
completely missing and it's
something to analyze.
ac921801-4673-4330-a447-ea53c9488427/9358-0
00:42:55.306 --> 00:42:59.851
It would be an interesting study
and it says the safety just from
ac921801-4673-4330-a447-ea53c9488427/9358-1
00:42:59.851 --> 00:43:01.916
the yes reporting time period.
ac921801-4673-4330-a447-ea53c9488427/9367-0
00:43:01.926 --> 00:43:05.256
And then it was like, so he's
missing anything.
ac921801-4673-4330-a447-ea53c9488427/9398-0
00:43:05.486 --> 00:43:10.142
So it was relocated with your
3D3 double difference tomography
ac921801-4673-4330-a447-ea53c9488427/9398-1
00:43:10.142 --> 00:43:13.836
model, and then you also use the
seismic station.
ac921801-4673-4330-a447-ea53c9488427/9426-0
00:43:13.926 --> 00:43:14.596
Yes as well.
ac921801-4673-4330-a447-ea53c9488427/9428-0
00:43:14.606 --> 00:43:17.727
For location, it's purely
seismic stations actually,
ac921801-4673-4330-a447-ea53c9488427/9428-1
00:43:17.727 --> 00:43:21.377
because they have a much better
like as in some coverage than
ac921801-4673-4330-a447-ea53c9488427/9428-2
00:43:21.377 --> 00:43:21.966
does does.
ac921801-4673-4330-a447-ea53c9488427/9464-0
00:43:21.976 --> 00:43:25.770
You can imagine like if you do
relocation with does you can
ac921801-4673-4330-a447-ea53c9488427/9464-1
00:43:25.770 --> 00:43:29.311
probably locate fairly well
anything here, but you know
ac921801-4673-4330-a447-ea53c9488427/9464-2
00:43:29.311 --> 00:43:30.196
anything here?
ac921801-4673-4330-a447-ea53c9488427/9469-0
00:43:30.206 --> 00:43:32.726
It would be somewhat by you
don't have like, great.
ac921801-4673-4330-a447-ea53c9488427/9476-0
00:43:33.026 --> 00:43:34.856
And I think we are covered.
ac921801-4673-4330-a447-ea53c9488427/9499-0
00:43:34.866 --> 00:43:38.303
That's the reason why we use
slightly like say you didn't use
ac921801-4673-4330-a447-ea53c9488427/9499-1
00:43:38.303 --> 00:43:39.966
your new 3D, yes, but obvious.
ac921801-4673-4330-a447-ea53c9488427/9501-0
00:43:39.976 --> 00:43:40.186
OK.
ac921801-4673-4330-a447-ea53c9488427/9508-0
00:43:40.196 --> 00:43:41.426
Yes, for the travel. Yes.
ac921801-4673-4330-a447-ea53c9488427/9510-0
00:43:41.736 --> 00:43:42.246
OK.
ac921801-4673-4330-a447-ea53c9488427/9519-0
00:43:42.256 --> 00:43:44.056
Thank you indeed.
ac921801-4673-4330-a447-ea53c9488427/9527-0
00:43:45.276 --> 00:43:47.646
And actually it doesn't even use
cross correlation.
ac921801-4673-4330-a447-ea53c9488427/9557-0
00:43:47.656 --> 00:43:51.401
So and that it can be even my
much better than this right with
ac921801-4673-4330-a447-ea53c9488427/9557-1
00:43:51.401 --> 00:43:55.146
cross correlation, this one is
just pure absolute travel time.
ac921801-4673-4330-a447-ea53c9488427/9560-0
00:43:55.156 --> 00:43:55.606
Three.
ac921801-4673-4330-a447-ea53c9488427/9562-0
00:43:55.676 --> 00:43:56.726
Yes, yes.
ac921801-4673-4330-a447-ea53c9488427/9602-0
00:43:57.116 --> 00:44:00.623
So I think there's quite a bit
of stuff can be done like you
ac921801-4673-4330-a447-ea53c9488427/9602-1
00:44:00.623 --> 00:44:04.187
always try to do the 1st order
improvement right or whatever,
ac921801-4673-4330-a447-ea53c9488427/9602-2
00:44:04.187 --> 00:44:05.566
you know how to do that.
ac921801-4673-4330-a447-ea53c9488427/9612-0
00:44:05.576 --> 00:44:07.076
I think that's really the
realize.
ac921801-4673-4330-a447-ea53c9488427/9639-0
00:44:08.456 --> 00:44:12.911
So we have a follow up question
here in the Yosemite room and
ac921801-4673-4330-a447-ea53c9488427/9624-0
00:44:12.116 --> 00:44:12.236
Yes.
ac921801-4673-4330-a447-ea53c9488427/9639-1
00:44:12.911 --> 00:44:17.006
right it's less a question and
more a follow up comment.
ac921801-4673-4330-a447-ea53c9488427/9642-0
00:44:17.796 --> 00:44:17.916
Yes.
ac921801-4673-4330-a447-ea53c9488427/9651-0
00:44:19.016 --> 00:44:21.566
Those earthquakes to the South
of the caldera.
ac921801-4673-4330-a447-ea53c9488427/9680-0
00:44:21.876 --> 00:44:25.839
Emily Montgomery Brown has a
nice paper on the first of those
ac921801-4673-4330-a447-ea53c9488427/9666-0
00:44:24.586 --> 00:44:24.876
Hmm.
ac921801-4673-4330-a447-ea53c9488427/9680-1
00:44:25.839 --> 00:44:28.076
earthquakes, and the Sierra
Block.
ac921801-4673-4330-a447-ea53c9488427/9691-0
00:44:28.866 --> 00:44:31.836
So yeah, yeah.
ac921801-4673-4330-a447-ea53c9488427/9682-0
00:44:28.956 --> 00:44:31.146
OK, I should look at that.
ac921801-4673-4330-a447-ea53c9488427/9693-0
00:44:31.256 --> 00:44:33.546
Yes, I think I have seen the
paper.
ac921801-4673-4330-a447-ea53c9488427/9707-0
00:44:33.556 --> 00:44:36.856
Yeah, I mean I yes, even like,
yeah, go ahead.
ac921801-4673-4330-a447-ea53c9488427/9704-0
00:44:35.196 --> 00:44:35.516
Yeah.
ac921801-4673-4330-a447-ea53c9488427/9719-0
00:44:37.496 --> 00:44:40.536
And for 2820, ten something.
ac921801-4673-4330-a447-ea53c9488427/9727-0
00:44:40.846 --> 00:44:42.556
So yeah, go go.
ac921801-4673-4330-a447-ea53c9488427/9725-0
00:44:41.066 --> 00:44:41.306
OK.
ac921801-4673-4330-a447-ea53c9488427/9730-0
00:44:42.356 --> 00:44:42.876
I I will.
ac921801-4673-4330-a447-ea53c9488427/9736-0
00:44:42.566 --> 00:44:43.176
Read that bigger.
ac921801-4673-4330-a447-ea53c9488427/9733-0
00:44:44.016 --> 00:44:44.546
I will.
ac921801-4673-4330-a447-ea53c9488427/9745-0
00:44:44.596 --> 00:44:45.926
I will that that's very good.
ac921801-4673-4330-a447-ea53c9488427/9805-0
00:44:45.936 --> 00:44:49.579
As I move towards like trying to
understand the seismicity I I
ac921801-4673-4330-a447-ea53c9488427/9805-1
00:44:49.579 --> 00:44:53.338
know there there has been a lot
of studies where they show, like
ac921801-4673-4330-a447-ea53c9488427/9805-2
00:44:53.338 --> 00:44:56.692
the Visalia think showed the
when you have percolation of
ac921801-4673-4330-a447-ea53c9488427/9805-3
00:44:56.692 --> 00:45:00.046
water from mild to you can
actually drive side immensity.
ac921801-4673-4330-a447-ea53c9488427/9821-0
00:45:00.056 --> 00:45:03.693
There are like some earthquakes
that are at least you know,
ac921801-4673-4330-a447-ea53c9488427/9821-1
00:45:03.693 --> 00:45:05.026
let's call them swarm.
ac921801-4673-4330-a447-ea53c9488427/9828-0
00:45:05.156 --> 00:45:05.756
And they're not.
ac921801-4673-4330-a447-ea53c9488427/9844-0
00:45:05.766 --> 00:45:08.520
They're not actually swarm, but
you have a trend of upgoing and
ac921801-4673-4330-a447-ea53c9488427/9844-1
00:45:08.520 --> 00:45:09.466
downgoing earthquakes.
ac921801-4673-4330-a447-ea53c9488427/9860-0
00:45:09.476 --> 00:45:12.586
Error size means city, so I know
it has been studied a lot.
ac921801-4673-4330-a447-ea53c9488427/9867-0
00:45:12.596 --> 00:45:14.776
So so yes.
ac921801-4673-4330-a447-ea53c9488427/9873-0
00:45:14.886 --> 00:45:16.656
But thank you for pointing the
paper out.
ac921801-4673-4330-a447-ea53c9488427/9888-0
00:45:16.666 --> 00:45:17.756
I I will have a look at that.
ac921801-4673-4330-a447-ea53c9488427/9917-0
00:45:19.056 --> 00:45:23.488
So we have another online
question in the chat from Jacob
ac921801-4673-4330-a447-ea53c9488427/9917-1
00:45:23.488 --> 00:45:28.226
Anderson in your East, West or
West E profile of Long Valley.
ac921801-4673-4330-a447-ea53c9488427/9964-0
00:45:28.236 --> 00:45:32.088
I am wondering if the BS and BP
VS variations in the near
ac921801-4673-4330-a447-ea53c9488427/9964-1
00:45:32.088 --> 00:45:36.205
surface are coincident with the
extension of the Hilton Creek
ac921801-4673-4330-a447-ea53c9488427/9964-2
00:45:36.205 --> 00:45:39.657
fault into the caldera as
inferred from gravity and
ac921801-4673-4330-a447-ea53c9488427/9964-3
00:45:39.657 --> 00:45:40.786
magnetic surveys.
ac921801-4673-4330-a447-ea53c9488427/9972-0
00:45:41.056 --> 00:45:41.916
Thanks for a great talk.
ac921801-4673-4330-a447-ea53c9488427/9979-0
00:45:42.956 --> 00:45:44.456
Yeah, that's a good point.
ac921801-4673-4330-a447-ea53c9488427/10016-0
00:45:44.466 --> 00:45:49.555
Like I kind of cherry picked
some of the study that they were
ac921801-4673-4330-a447-ea53c9488427/10016-1
00:45:49.555 --> 00:45:54.726
like a, you know, useful for me
to analyze the and the result.
ac921801-4673-4330-a447-ea53c9488427/10063-0
00:45:54.876 --> 00:45:58.416
I think that there is way more
stuff and actually at the model
ac921801-4673-4330-a447-ea53c9488427/10063-1
00:45:58.416 --> 00:46:01.900
is is published in any people
can download it and have a look
ac921801-4673-4330-a447-ea53c9488427/10063-2
00:46:01.900 --> 00:46:05.440
at it and hopefully like we we
can see more correlation and it
ac921801-4673-4330-a447-ea53c9488427/10063-3
00:46:05.440 --> 00:46:07.126
might be useful in the future.
ac921801-4673-4330-a447-ea53c9488427/10079-0
00:46:07.196 --> 00:46:10.015
But yeah, I haven't looked at
that stuff and it it's it's an
ac921801-4673-4330-a447-ea53c9488427/10079-1
00:46:10.015 --> 00:46:10.846
interesting point.
ac921801-4673-4330-a447-ea53c9488427/10085-0
00:46:10.956 --> 00:46:11.806
It would be interesting.
ac921801-4673-4330-a447-ea53c9488427/10129-0
00:46:11.816 --> 00:46:14.863
One thing that we were
discussing with a student is
ac921801-4673-4330-a447-ea53c9488427/10129-1
00:46:14.863 --> 00:46:17.910
trying to use surface wave
noise, cross correlation
ac921801-4673-4330-a447-ea53c9488427/10129-2
00:46:17.910 --> 00:46:21.601
tomography between Dallas and
the station, and try to actually
ac921801-4673-4330-a447-ea53c9488427/10129-3
00:46:21.601 --> 00:46:24.296
have a much better resolution of
the shallow.
ac921801-4673-4330-a447-ea53c9488427/10171-0
00:46:24.486 --> 00:46:28.269
You can see that here there
resolution at the shallow I mean
ac921801-4673-4330-a447-ea53c9488427/10171-1
00:46:28.269 --> 00:46:32.114
it's good up to 10 kilometers,
but then maybe like we've just
ac921801-4673-4330-a447-ea53c9488427/10171-2
00:46:32.114 --> 00:46:35.338
surface wave noise correlation,
we can improve very
ac921801-4673-4330-a447-ea53c9488427/10171-3
00:46:35.338 --> 00:46:36.206
significantly.
ac921801-4673-4330-a447-ea53c9488427/10193-0
00:46:36.286 --> 00:46:40.671
The first one to two kilometer
at a way higher resolution, and
ac921801-4673-4330-a447-ea53c9488427/10193-1
00:46:40.671 --> 00:46:43.106
the hope is to use maybe like
you.
ac921801-4673-4330-a447-ea53c9488427/10227-0
00:46:43.616 --> 00:46:47.159
One thing that I know for sure
is that when you cross
ac921801-4673-4330-a447-ea53c9488427/10227-1
00:46:47.159 --> 00:46:51.095
correlate, does and vertical
component station you get nice
ac921801-4673-4330-a447-ea53c9488427/10227-2
00:46:51.095 --> 00:46:54.966
cross correlation and it works
very well and why it works.
ac921801-4673-4330-a447-ea53c9488427/10232-0
00:46:55.306 --> 00:46:56.286
It's a different story.
ac921801-4673-4330-a447-ea53c9488427/10270-0
00:46:56.296 --> 00:47:01.166
I think I have my ideas but but
it would be nice to make it, you
ac921801-4673-4330-a447-ea53c9488427/10270-1
00:47:01.166 --> 00:47:05.436
know in that way and try to
resolve both these structure
ac921801-4673-4330-a447-ea53c9488427/10270-2
00:47:05.436 --> 00:47:09.406
with surface waves and economic
demography together.
ac921801-4673-4330-a447-ea53c9488427/10306-0
00:47:09.476 --> 00:47:13.030
Actually that that would be
really like a interesting,
ac921801-4673-4330-a447-ea53c9488427/10306-1
00:47:13.030 --> 00:47:16.841
because then you have like a
higher resolution at the very
ac921801-4673-4330-a447-ea53c9488427/10306-2
00:47:16.841 --> 00:47:20.136
top and then like a good
resolution throughout the
ac921801-4673-4330-a447-ea53c9488427/10306-3
00:47:20.136 --> 00:47:20.976
system, yeah.
ac921801-4673-4330-a447-ea53c9488427/10316-0
00:47:23.286 --> 00:47:23.726
OK.
ac921801-4673-4330-a447-ea53c9488427/10327-0
00:47:23.736 --> 00:47:26.992
I will take another question
from the room if something
ac921801-4673-4330-a447-ea53c9488427/10327-1
00:47:26.992 --> 00:47:28.096
happened right now.
ac921801-4673-4330-a447-ea53c9488427/10365-0
00:47:28.106 --> 00:47:32.507
Since seismicity occurred right
now, I'm wondering how quickly
ac921801-4673-4330-a447-ea53c9488427/10365-1
00:47:32.507 --> 00:47:36.908
you would be able to recognize
that change in tomography, like
ac921801-4673-4330-a447-ea53c9488427/10363-0
00:47:36.016 --> 00:47:37.546
Ah, that yes.
ac921801-4673-4330-a447-ea53c9488427/10365-2
00:47:36.908 --> 00:47:37.606
if you're.
ac921801-4673-4330-a447-ea53c9488427/10369-0
00:47:37.636 --> 00:47:39.946
Internet of velocity velocity
changes.
ac921801-4673-4330-a447-ea53c9488427/10375-0
00:47:41.246 --> 00:47:41.366
Yes.
ac921801-4673-4330-a447-ea53c9488427/10379-0
00:47:42.376 --> 00:47:44.086
That's a very good point.
ac921801-4673-4330-a447-ea53c9488427/10382-0
00:47:44.096 --> 00:47:46.566
Uh, maybe.
ac921801-4673-4330-a447-ea53c9488427/10392-0
00:47:46.616 --> 00:47:48.316
Yeah, I mean, OK, it depends.
ac921801-4673-4330-a447-ea53c9488427/10403-0
00:47:48.466 --> 00:47:52.756
I know in Iceland we recorded
with noise cross correlations.
ac921801-4673-4330-a447-ea53c9488427/10413-0
00:47:52.766 --> 00:47:55.736
We are student is is writing the
manuscript.
ac921801-4673-4330-a447-ea53c9488427/10439-0
00:47:55.746 --> 00:48:00.169
Now we can clearly see very
significant TV over V changes
ac921801-4673-4330-a447-ea53c9488427/10439-1
00:48:00.169 --> 00:48:03.676
before and after the under every
year option.
ac921801-4673-4330-a447-ea53c9488427/10466-0
00:48:04.046 --> 00:48:08.806
So that's visible the maybe it's
possible to do the same here.
ac921801-4673-4330-a447-ea53c9488427/10476-0
00:48:09.236 --> 00:48:14.337
The my only concern of this is
seems it's a very large system
ac921801-4673-4330-a447-ea53c9488427/10476-1
00:48:14.337 --> 00:48:17.546
and I think it's evolving very
slowly.
ac921801-4673-4330-a447-ea53c9488427/10504-0
00:48:17.866 --> 00:48:21.642
Maybe like from my economic
tomography perspective, I think
ac921801-4673-4330-a447-ea53c9488427/10504-1
00:48:21.642 --> 00:48:25.543
it would be very challenging
unless you have many, many years
ac921801-4673-4330-a447-ea53c9488427/10504-2
00:48:25.543 --> 00:48:26.046
of data.
ac921801-4673-4330-a447-ea53c9488427/10536-0
00:48:26.056 --> 00:48:30.016
And I it depends on the change
of the velocity, because if it's
ac921801-4673-4330-a447-ea53c9488427/10536-1
00:48:30.016 --> 00:48:33.605
a small change in velocity, it's
below your ability to be
ac921801-4673-4330-a447-ea53c9488427/10536-2
00:48:33.605 --> 00:48:36.636
resolved even from a an
uncertainty perspective.
ac921801-4673-4330-a447-ea53c9488427/10555-0
00:48:37.066 --> 00:48:43.376
Uh, it's a it maybe like surface
wave changes.
ac921801-4673-4330-a447-ea53c9488427/10594-0
00:48:43.466 --> 00:48:48.093
It might be more reliable with
some kind of DV overview, but I
ac921801-4673-4330-a447-ea53c9488427/10594-1
00:48:48.093 --> 00:48:52.573
know and many people ask me if
you you could do a time lapse
ac921801-4673-4330-a447-ea53c9488427/10594-2
00:48:52.573 --> 00:48:54.776
demography of the Long Valley.
ac921801-4673-4330-a447-ea53c9488427/10610-0
00:48:54.966 --> 00:48:57.888
Maybe, but I think it's kind of
challenging because this system
ac921801-4673-4330-a447-ea53c9488427/10610-1
00:48:57.888 --> 00:48:58.436
is evolving.
ac921801-4673-4330-a447-ea53c9488427/10640-0
00:48:58.506 --> 00:49:02.175
You know, maybe better than
myself if I feel it's evolving
ac921801-4673-4330-a447-ea53c9488427/10640-1
00:49:02.175 --> 00:49:05.782
very slowly, it's one better
candidate to do this kind of
ac921801-4673-4330-a447-ea53c9488427/10640-2
00:49:05.782 --> 00:49:07.336
stuff is maybe kill away.
ac921801-4673-4330-a447-ea53c9488427/10649-0
00:49:07.536 --> 00:49:09.316
Yeah, but we have a lot of data.
ac921801-4673-4330-a447-ea53c9488427/10713-0
00:49:09.566 --> 00:49:13.394
It's a system that is evolving
very quickly over time, and
ac921801-4673-4330-a447-ea53c9488427/10713-1
00:49:13.394 --> 00:49:16.897
maybe by doing, you know,
tomography before and after
ac921801-4673-4330-a447-ea53c9488427/10713-2
00:49:16.897 --> 00:49:20.919
giving eruption, it might be
able to to resolve change or the
ac921801-4673-4330-a447-ea53c9488427/10713-3
00:49:20.919 --> 00:49:24.357
change in velocity is
significant enough that can be
ac921801-4673-4330-a447-ea53c9488427/10713-4
00:49:24.357 --> 00:49:28.638
resolved, but for a long valley,
I think it's kind of challenging
ac921801-4673-4330-a447-ea53c9488427/10713-5
00:49:28.638 --> 00:49:29.546
in my opinion.
ac921801-4673-4330-a447-ea53c9488427/10747-0
00:49:29.556 --> 00:49:33.633
But you know, maybe some people
might prove this idea wrong
ac921801-4673-4330-a447-ea53c9488427/10747-1
00:49:33.633 --> 00:49:37.371
there, but yeah, it's a again
like you need to make an
ac921801-4673-4330-a447-ea53c9488427/10747-2
00:49:37.371 --> 00:49:38.186
observation.
ac921801-4673-4330-a447-ea53c9488427/10773-0
00:49:38.196 --> 00:49:41.349
And then if you see the
observation and you're convinced
ac921801-4673-4330-a447-ea53c9488427/10773-1
00:49:41.349 --> 00:49:42.566
by that you you could.
ac921801-4673-4330-a447-ea53c9488427/10826-0
00:49:42.576 --> 00:49:47.426
One can try to invert it and but
I feel maybe D V / V is more
ac921801-4673-4330-a447-ea53c9488427/10826-1
00:49:47.426 --> 00:49:52.433
likely candidate to try to see
this kind of changes in the long
ac921801-4673-4330-a447-ea53c9488427/10826-2
00:49:52.433 --> 00:49:57.439
run because there it's a very,
very good question and it's hard
ac921801-4673-4330-a447-ea53c9488427/10826-3
00:49:57.439 --> 00:50:01.976
to to see what or to know
whether it's gonna work or not,
ac921801-4673-4330-a447-ea53c9488427/10826-4
00:50:01.976 --> 00:50:04.166
but it's a very good person.
ac921801-4673-4330-a447-ea53c9488427/10838-0
00:50:06.126 --> 00:50:08.346
If there's an online question
from Dave Shelly.
ac921801-4673-4330-a447-ea53c9488427/10839-0
00:50:08.996 --> 00:50:09.116
Yes.
ac921801-4673-4330-a447-ea53c9488427/10842-0
00:50:11.926 --> 00:50:12.136
Hey.
ac921801-4673-4330-a447-ea53c9488427/10844-0
00:50:12.146 --> 00:50:12.296
Yeah.
ac921801-4673-4330-a447-ea53c9488427/10852-0
00:50:12.306 --> 00:50:13.336
Thanks very much for the talk.
ac921801-4673-4330-a447-ea53c9488427/10857-0
00:50:13.346 --> 00:50:15.186
That's really impressive work.
ac921801-4673-4330-a447-ea53c9488427/10912-0
00:50:15.546 --> 00:50:19.602
You talk mostly about the
tomography results, but it seems
ac921801-4673-4330-a447-ea53c9488427/10912-1
00:50:19.602 --> 00:50:23.313
like one maybe untapped
potential of the DAS is to be
ac921801-4673-4330-a447-ea53c9488427/10912-2
00:50:23.313 --> 00:50:27.575
able to really locate some of
these reflected phases that you
ac921801-4673-4330-a447-ea53c9488427/10901-0
00:50:26.416 --> 00:50:26.776
Umm.
ac921801-4673-4330-a447-ea53c9488427/10912-3
00:50:27.575 --> 00:50:31.630
might expect off the top of a
big velocity contrast like a
ac921801-4673-4330-a447-ea53c9488427/10912-4
00:50:31.630 --> 00:50:32.386
magma body.
ac921801-4673-4330-a447-ea53c9488427/10915-0
00:50:32.636 --> 00:50:32.826
Yeah.
ac921801-4673-4330-a447-ea53c9488427/10918-0
00:50:33.526 --> 00:50:35.876
And you know, you see those
beautiful.
ac921801-4673-4330-a447-ea53c9488427/10939-0
00:50:37.806 --> 00:50:40.026
You know, essentially, yeah,
those types of plots.
ac921801-4673-4330-a447-ea53c9488427/10932-0
00:50:39.746 --> 00:50:40.756
You even here?
ac921801-4673-4330-a447-ea53c9488427/10950-0
00:50:40.806 --> 00:50:41.796
Yeah, I know what you mean.
ac921801-4673-4330-a447-ea53c9488427/10943-0
00:50:41.156 --> 00:50:41.606
Yeah.
ac921801-4673-4330-a447-ea53c9488427/10945-0
00:50:41.616 --> 00:50:42.106
Yeah.
ac921801-4673-4330-a447-ea53c9488427/10960-0
00:50:41.946 --> 00:50:42.886
This guy I know.
ac921801-4673-4330-a447-ea53c9488427/10983-0
00:50:42.176 --> 00:50:45.766
So is that is that something
you're thinking about or you
ac921801-4673-4330-a447-ea53c9488427/10983-1
00:50:45.766 --> 00:50:49.046
have any comment on potential
for that kind of work?
ac921801-4673-4330-a447-ea53c9488427/10979-0
00:50:49.066 --> 00:50:49.676
Yeah.
ac921801-4673-4330-a447-ea53c9488427/10999-0
00:50:49.846 --> 00:50:54.208
Yes, actually like a that a
student started working a little
ac921801-4673-4330-a447-ea53c9488427/10999-1
00:50:54.208 --> 00:50:55.066
bit on that.
ac921801-4673-4330-a447-ea53c9488427/11023-0
00:50:55.136 --> 00:50:59.879
It's we we tried and then we
kind of gave up for a little bit
ac921801-4673-4330-a447-ea53c9488427/11023-1
00:50:59.879 --> 00:51:01.026
because it was.
ac921801-4673-4330-a447-ea53c9488427/11093-0
00:51:01.096 --> 00:51:05.363
It's challenging because if you
try to do a simple say, you
ac921801-4673-4330-a447-ea53c9488427/11093-1
00:51:05.363 --> 00:51:09.771
know, call it kirkov migration,
just stacking even the image,
ac921801-4673-4330-a447-ea53c9488427/11093-2
00:51:09.771 --> 00:51:14.251
like the energy or the waveform,
it's kind of hard because the
ac921801-4673-4330-a447-ea53c9488427/11093-3
00:51:14.251 --> 00:51:18.589
you're not recording the body
wave of the wave field, so you
ac921801-4673-4330-a447-ea53c9488427/11093-4
00:51:18.589 --> 00:51:23.211
do, but it's actually underneath
this, you know, salt and pepper
ac921801-4673-4330-a447-ea53c9488427/11093-5
00:51:23.211 --> 00:51:24.206
scatter waves.
ac921801-4673-4330-a447-ea53c9488427/11098-0
00:51:25.006 --> 00:51:26.556
We tried with cross correlation.
ac921801-4673-4330-a447-ea53c9488427/11113-0
00:51:26.566 --> 00:51:29.716
I think it's it would be
amazing, I think.
ac921801-4673-4330-a447-ea53c9488427/11142-0
00:51:29.886 --> 00:51:33.922
OK, let me tell you for long,
for Los Angeles basing, I can
ac921801-4673-4330-a447-ea53c9488427/11124-0
00:51:30.286 --> 00:51:30.576
OK.
ac921801-4673-4330-a447-ea53c9488427/11142-1
00:51:33.922 --> 00:51:37.016
clearly see multiples and
they're very clear.
ac921801-4673-4330-a447-ea53c9488427/11172-0
00:51:37.106 --> 00:51:40.683
And I think those I know they
can be used for reverse time
ac921801-4673-4330-a447-ea53c9488427/11172-1
00:51:40.683 --> 00:51:43.956
migration or some kind of images
of the basin itself.
ac921801-4673-4330-a447-ea53c9488427/11182-0
00:51:44.026 --> 00:51:47.056
And I'm working on trying to get
that around.
ac921801-4673-4330-a447-ea53c9488427/11189-0
00:51:47.986 --> 00:51:49.816
In this case, the tricky part.
ac921801-4673-4330-a447-ea53c9488427/11200-0
00:51:49.826 --> 00:51:51.906
Yes, it would be amazing if it
can be done.
ac921801-4673-4330-a447-ea53c9488427/11238-0
00:51:52.406 --> 00:51:55.965
There is a little bit of
technical challenge on how to do
ac921801-4673-4330-a447-ea53c9488427/11238-1
00:51:55.965 --> 00:51:57.806
it, like how to really strike.
ac921801-4673-4330-a447-ea53c9488427/11271-0
00:51:57.816 --> 00:52:01.243
Well, maybe it just cross
correlation of the body with,
ac921801-4673-4330-a447-ea53c9488427/11271-1
00:52:01.243 --> 00:52:05.037
you know, as wave body waves and
try to get like a nice cross
ac921801-4673-4330-a447-ea53c9488427/11271-2
00:52:05.037 --> 00:52:08.526
correlation of the secondary
phases and the hard part, I
ac921801-4673-4330-a447-ea53c9488427/11271-3
00:52:08.526 --> 00:52:10.606
think it's a simple panic
system.
ac921801-4673-4330-a447-ea53c9488427/11286-0
00:52:10.616 --> 00:52:14.046
So these reflector are like
continuous for a little bit.
ac921801-4673-4330-a447-ea53c9488427/11311-0
00:52:14.056 --> 00:52:16.806
Then there is some other
structure, so it's a.
ac921801-4673-4330-a447-ea53c9488427/11339-0
00:52:17.476 --> 00:52:21.267
It's not as simple if you may as
the Los Angeles Basin, which we
ac921801-4673-4330-a447-ea53c9488427/11339-1
00:52:21.267 --> 00:52:24.825
know is very, you know it's a
big reflector, it's very large
ac921801-4673-4330-a447-ea53c9488427/11339-2
00:52:24.825 --> 00:52:26.516
and it's somewhat continuous.
ac921801-4673-4330-a447-ea53c9488427/11348-0
00:52:27.166 --> 00:52:28.556
In this case, it would be
amazing.
ac921801-4673-4330-a447-ea53c9488427/11352-0
00:52:28.566 --> 00:52:30.056
Yes, it's we tried.
ac921801-4673-4330-a447-ea53c9488427/11372-0
00:52:30.766 --> 00:52:34.075
We cannot give up for the
moment, but yes, it's it's a
ac921801-4673-4330-a447-ea53c9488427/11372-1
00:52:34.075 --> 00:52:34.616
very yes.
ac921801-4673-4330-a447-ea53c9488427/11382-0
00:52:34.626 --> 00:52:36.176
It's an untap I agree with you.
ac921801-4673-4330-a447-ea53c9488427/11393-0
00:52:36.226 --> 00:52:39.636
It's something that it should be
exploring the future.
ac921801-4673-4330-a447-ea53c9488427/11441-0
00:52:39.686 --> 00:52:43.264
Maybe like Long Valley is still
a little challenging because of
ac921801-4673-4330-a447-ea53c9488427/11441-1
00:52:43.264 --> 00:52:46.786
it's a it's a volcanic system,
so it's complicated to to trust
ac921801-4673-4330-a447-ea53c9488427/11441-2
00:52:46.786 --> 00:52:50.364
what you see, but or maybe I'm
wrong and I just we are not good
ac921801-4673-4330-a447-ea53c9488427/11441-3
00:52:50.364 --> 00:52:52.656
enough to construct the
potential there.
ac921801-4673-4330-a447-ea53c9488427/11465-0
00:52:52.706 --> 00:52:57.445
So but it's yes, it's something
that we tried in this case long
ac921801-4673-4330-a447-ea53c9488427/11465-1
00:52:57.445 --> 00:52:58.926
as Angeles Bayesian.
ac921801-4673-4330-a447-ea53c9488427/11519-0
00:52:58.936 --> 00:53:02.817
It's a much better candidate to
to show this potential and agree
ac921801-4673-4330-a447-ea53c9488427/11519-1
00:53:02.817 --> 00:53:06.638
if if this secondary phases are
clear, it's yes, it's something
ac921801-4673-4330-a447-ea53c9488427/11519-2
00:53:06.638 --> 00:53:10.280
that it's very hard to do with
just stations, right, because
ac921801-4673-4330-a447-ea53c9488427/11519-3
00:53:10.280 --> 00:53:14.101
it's hard to know whether it's
our weird phase or is actually a
ac921801-4673-4330-a447-ea53c9488427/11519-4
00:53:14.101 --> 00:53:15.056
secondary phase.
ac921801-4673-4330-a447-ea53c9488427/11531-0
00:53:15.506 --> 00:53:17.226
So it's a great point.
ac921801-4673-4330-a447-ea53c9488427/11526-0
00:53:16.586 --> 00:53:16.796
Yeah.
ac921801-4673-4330-a447-ea53c9488427/11535-0
00:53:17.816 --> 00:53:19.136
Yeah, we we saw.
ac921801-4673-4330-a447-ea53c9488427/11568-0
00:53:19.186 --> 00:53:23.218
I worked with Nikada several
years ago and we saw, you know,
ac921801-4673-4330-a447-ea53c9488427/11552-0
00:53:21.466 --> 00:53:21.646
Mm-hmm.
ac921801-4673-4330-a447-ea53c9488427/11568-1
00:53:23.218 --> 00:53:26.853
what seemed to be clear
reflective face from a a swarm
ac921801-4673-4330-a447-ea53c9488427/11561-0
00:53:23.996 --> 00:53:24.116
Yes.
ac921801-4673-4330-a447-ea53c9488427/11568-2
00:53:26.853 --> 00:53:27.646
event there.
ac921801-4673-4330-a447-ea53c9488427/11588-0
00:53:27.656 --> 00:53:30.322
But you know, we were looking at
a single vertical component
ac921801-4673-4330-a447-ea53c9488427/11588-1
00:53:30.322 --> 00:53:32.026
station and it was really
frustrating.
ac921801-4673-4330-a447-ea53c9488427/11607-0
00:53:32.116 --> 00:53:35.536
So this this would be a great
data set to explore. Thanks.
ac921801-4673-4330-a447-ea53c9488427/11610-0
00:53:35.096 --> 00:53:36.566
Yes, yes, I know.
ac921801-4673-4330-a447-ea53c9488427/11616-0
00:53:36.576 --> 00:53:37.606
I know the paper your.
ac921801-4673-4330-a447-ea53c9488427/11620-0
00:53:37.616 --> 00:53:37.986
Yes.
ac921801-4673-4330-a447-ea53c9488427/11677-0
00:53:37.996 --> 00:53:41.897
And you guys did a reverse time
migration, so that that's the
ac921801-4673-4330-a447-ea53c9488427/11677-1
00:53:41.897 --> 00:53:45.987
hard part here is how to extract
this you know coherency because
ac921801-4673-4330-a447-ea53c9488427/11677-2
00:53:45.987 --> 00:53:49.762
you can see you kind of see it
by naked eyes, but then it's
ac921801-4673-4330-a447-ea53c9488427/11677-3
00:53:49.762 --> 00:53:51.146
like yeah, it's there.
ac921801-4673-4330-a447-ea53c9488427/11684-0
00:53:51.156 --> 00:53:54.314
It's not there like and I feel
maybe cross correlation or some
ac921801-4673-4330-a447-ea53c9488427/11684-1
00:53:54.314 --> 00:53:55.416
kind of deconvolution.
ac921801-4673-4330-a447-ea53c9488427/11704-0
00:53:55.496 --> 00:53:59.051
There must be some very simple,
simple or some kind of method
ac921801-4673-4330-a447-ea53c9488427/11704-1
00:53:59.051 --> 00:54:00.886
that allows you to extract that.
ac921801-4673-4330-a447-ea53c9488427/11714-0
00:54:00.946 --> 00:54:03.106
If you can see it in the data,
it's there.
ac921801-4673-4330-a447-ea53c9488427/11744-0
00:54:03.396 --> 00:54:06.977
It's just a matter of being
smart enough to instructed in a
ac921801-4673-4330-a447-ea53c9488427/11744-1
00:54:06.977 --> 00:54:10.319
Korean right way and then
perform whatever imaging tool
ac921801-4673-4330-a447-ea53c9488427/11744-2
00:54:10.319 --> 00:54:10.856
you have.
ac921801-4673-4330-a447-ea53c9488427/11749-0
00:54:10.906 --> 00:54:12.056
Yes, yeah.
ac921801-4673-4330-a447-ea53c9488427/11754-0
00:54:13.006 --> 00:54:13.596
Thanks for the talk.
ac921801-4673-4330-a447-ea53c9488427/11752-0
00:54:14.306 --> 00:54:14.756
Yeah.
ac921801-4673-4330-a447-ea53c9488427/11760-0
00:54:14.806 --> 00:54:15.186
Thank you.
ac921801-4673-4330-a447-ea53c9488427/11788-0
00:54:16.456 --> 00:54:19.849
It would take one last question
here in the room I have a
ac921801-4673-4330-a447-ea53c9488427/11776-0
00:54:19.536 --> 00:54:19.716
OK.
ac921801-4673-4330-a447-ea53c9488427/11788-1
00:54:19.849 --> 00:54:22.656
questions, kind of a follow up
to David Shelly.
ac921801-4673-4330-a447-ea53c9488427/11802-0
00:54:22.666 --> 00:54:27.340
He's first of all, a really
impressive presentation and tell
ac921801-4673-4330-a447-ea53c9488427/11802-1
00:54:27.340 --> 00:54:28.566
me if you agree.
ac921801-4673-4330-a447-ea53c9488427/11821-0
00:54:28.956 --> 00:54:32.484
It seems to me you've made a
persuasive case for the
ac921801-4673-4330-a447-ea53c9488427/11821-1
00:54:32.484 --> 00:54:34.946
existence of this high velocity
lid.
ac921801-4673-4330-a447-ea53c9488427/11846-0
00:54:35.406 --> 00:54:41.592
Uh, I'm not sure whether it's
definitive in the sense that,
ac921801-4673-4330-a447-ea53c9488427/11846-1
00:54:41.592 --> 00:54:44.376
uh, you've found the model.
ac921801-4673-4330-a447-ea53c9488427/11922-0
00:54:44.386 --> 00:54:49.794
It's not a unique model as you
would agree, it depends a little
ac921801-4673-4330-a447-ea53c9488427/11862-0
00:54:47.216 --> 00:54:47.316
Yes.
ac921801-4673-4330-a447-ea53c9488427/11922-1
00:54:49.794 --> 00:54:55.032
bit on the starting model that
you the initial model that you
ac921801-4673-4330-a447-ea53c9488427/11922-2
00:54:55.032 --> 00:54:59.932
use and and then the non
uniqueness of tomography is that
ac921801-4673-4330-a447-ea53c9488427/11922-3
00:54:59.932 --> 00:55:05.340
is that a fair comment is that
reflect what you're thinking and
ac921801-4673-4330-a447-ea53c9488427/11922-4
00:55:05.340 --> 00:55:10.747
but are there you explored with
David Shelly's question ways of
ac921801-4673-4330-a447-ea53c9488427/11922-5
00:55:10.747 --> 00:55:13.366
trying to nail it definitively.
ac921801-4673-4330-a447-ea53c9488427/11932-0
00:55:14.296 --> 00:55:16.646
That that's yes, I totally agree
with you.
ac921801-4673-4330-a447-ea53c9488427/11998-0
00:55:16.696 --> 00:55:20.496
Indeed, the starting model
affect the inverted the results
ac921801-4673-4330-a447-ea53c9488427/11998-1
00:55:20.496 --> 00:55:24.231
and there is one thing I tried
to start the tomorrow with
ac921801-4673-4330-a447-ea53c9488427/11998-2
00:55:24.231 --> 00:55:28.353
because in this case we started
I I didn't mention clearly, but
ac921801-4673-4330-a447-ea53c9488427/11998-3
00:55:28.353 --> 00:55:32.152
we started from a 3D surface
wave tomography model that is
ac921801-4673-4330-a447-ea53c9488427/11998-4
00:55:32.152 --> 00:55:34.406
from the Community velocity
model.
ac921801-4673-4330-a447-ea53c9488427/12006-0
00:55:34.976 --> 00:55:36.946
I started with A1V velocity
model.
ac921801-4673-4330-a447-ea53c9488427/12021-0
00:55:36.956 --> 00:55:41.377
I hope I included in the
supplementary figure it it looks
ac921801-4673-4330-a447-ea53c9488427/12021-1
00:55:41.377 --> 00:55:41.986
similar.
ac921801-4673-4330-a447-ea53c9488427/12031-0
00:55:42.236 --> 00:55:44.136
Not exactly the same, I hope I
did.
ac921801-4673-4330-a447-ea53c9488427/12039-0
00:55:44.506 --> 00:55:45.606
Yeah, these are no.
ac921801-4673-4330-a447-ea53c9488427/12043-0
00:55:45.616 --> 00:55:46.376
Of course I didn't.
ac921801-4673-4330-a447-ea53c9488427/12050-0
00:55:48.376 --> 00:55:49.056
It's ohh.
ac921801-4673-4330-a447-ea53c9488427/12064-0
00:55:48.986 --> 00:55:49.746
OK, OK.
ac921801-4673-4330-a447-ea53c9488427/12055-0
00:55:49.066 --> 00:55:49.406
No, no, no.
ac921801-4673-4330-a447-ea53c9488427/12059-0
00:55:49.456 --> 00:55:50.046
Maybe yes.
ac921801-4673-4330-a447-ea53c9488427/12066-0
00:55:50.056 --> 00:55:51.726
Maybe, maybe, maybe one second.
ac921801-4673-4330-a447-ea53c9488427/12079-0
00:55:51.836 --> 00:55:54.086
Yeah, just too many additional
slides.
ac921801-4673-4330-a447-ea53c9488427/12102-0
00:55:54.716 --> 00:56:00.252
And so actually with the initial
model, you see like we've, uh,
ac921801-4673-4330-a447-ea53c9488427/12102-1
00:56:00.252 --> 00:56:03.366
won the model you it's not as
good.
ac921801-4673-4330-a447-ea53c9488427/12109-0
00:56:03.376 --> 00:56:04.946
You can see similar structure.
ac921801-4673-4330-a447-ea53c9488427/12117-0
00:56:05.906 --> 00:56:07.616
Uh, But he's not as clear.
ac921801-4673-4330-a447-ea53c9488427/12184-0
00:56:07.626 --> 00:56:13.149
I totally agree with you that
the initial model effects a lot
ac921801-4673-4330-a447-ea53c9488427/12184-1
00:56:13.149 --> 00:56:18.850
the inverted the results and so
yes indeed, like there might be
ac921801-4673-4330-a447-ea53c9488427/12184-2
00:56:18.850 --> 00:56:24.462
some bias in that and so it's
something that we should explore
ac921801-4673-4330-a447-ea53c9488427/12184-3
00:56:24.462 --> 00:56:29.895
more and maybe like again like
with the secondary phase, you
ac921801-4673-4330-a447-ea53c9488427/12184-4
00:56:29.895 --> 00:56:34.616
can note it down and really say
yes, that's correct.
ac921801-4673-4330-a447-ea53c9488427/12197-0
00:56:34.706 --> 00:56:37.369
The other thing that we are
exploring with another student
ac921801-4673-4330-a447-ea53c9488427/12197-1
00:56:37.369 --> 00:56:38.046
is uncertainty.
ac921801-4673-4330-a447-ea53c9488427/12210-0
00:56:38.156 --> 00:56:40.726
One thing that is completely
missing from this study is
ac921801-4673-4330-a447-ea53c9488427/12210-1
00:56:40.726 --> 00:56:41.276
uncertainty.
ac921801-4673-4330-a447-ea53c9488427/12282-0
00:56:41.486 --> 00:56:46.217
We don't know how umm, or how
certain we are about some of the
ac921801-4673-4330-a447-ea53c9488427/12282-1
00:56:46.217 --> 00:56:50.572
structure we see and we've a
student we are, we have this
ac921801-4673-4330-a447-ea53c9488427/12282-2
00:56:50.572 --> 00:56:54.551
method that can handle
uncertainty based on economic
ac921801-4673-4330-a447-ea53c9488427/12282-3
00:56:54.551 --> 00:56:59.056
tomography and we did a study
where working on a Kilauea to
ac921801-4673-4330-a447-ea53c9488427/12282-4
00:56:59.056 --> 00:57:03.636
get something out to just show
the potential of of this the.
ac921801-4673-4330-a447-ea53c9488427/12288-0
00:57:05.296 --> 00:57:06.476
But that's completely missing.
ac921801-4673-4330-a447-ea53c9488427/12313-0
00:57:06.486 --> 00:57:09.429
Hopefully like with this more
because as you said it, it
ac921801-4673-4330-a447-ea53c9488427/12313-1
00:57:09.429 --> 00:57:10.926
depends on the initial model.
ac921801-4673-4330-a447-ea53c9488427/12326-0
00:57:10.976 --> 00:57:14.116
Hopefully we've some kind of
sampling method.
ac921801-4673-4330-a447-ea53c9488427/12353-0
00:57:14.546 --> 00:57:18.088
You can get a better idea of the
uncertainty at work or which
ac921801-4673-4330-a447-ea53c9488427/12353-1
00:57:18.088 --> 00:57:21.516
other model could explain the
travel time that you observe.
ac921801-4673-4330-a447-ea53c9488427/12387-0
00:57:22.046 --> 00:57:27.215
But yes, this is one of the many
pictures that you could get from
ac921801-4673-4330-a447-ea53c9488427/12387-1
00:57:27.215 --> 00:57:32.227
the set of data we have and it
seems to fit or their narratives
ac921801-4673-4330-a447-ea53c9488427/12387-2
00:57:32.227 --> 00:57:33.166
in the area.
ac921801-4673-4330-a447-ea53c9488427/12431-0
00:57:33.256 --> 00:57:37.760
So, but yes, it's of course
there is some kind of bias if
ac921801-4673-4330-a447-ea53c9488427/12431-1
00:57:37.760 --> 00:57:42.031
you made so we will see how I
think they're start some
ac921801-4673-4330-a447-ea53c9488427/12431-2
00:57:42.031 --> 00:57:46.923
technical improvement and ways
of to do tomography in a better
ac921801-4673-4330-a447-ea53c9488427/12431-3
00:57:46.923 --> 00:57:47.466
manner.
ac921801-4673-4330-a447-ea53c9488427/12433-0
00:57:47.826 --> 00:57:48.516
Yeah.
ac921801-4673-4330-a447-ea53c9488427/12475-0
00:57:48.776 --> 00:57:52.623
And again, like I feel like
uncertainty is one of them, but
ac921801-4673-4330-a447-ea53c9488427/12475-1
00:57:52.623 --> 00:57:56.534
and maybe secondary phases to
really say yes, this structure
ac921801-4673-4330-a447-ea53c9488427/12475-2
00:57:56.534 --> 00:58:00.188
is real because we can see
actually your secondary phase
ac921801-4673-4330-a447-ea53c9488427/12475-3
00:58:00.188 --> 00:58:01.406
coming out of that.
ac921801-4673-4330-a447-ea53c9488427/12486-0
00:58:01.666 --> 00:58:04.166
So that so there's still work to
do.
ac921801-4673-4330-a447-ea53c9488427/12489-0
00:58:04.176 --> 00:58:04.876
It's not that.
ac921801-4673-4330-a447-ea53c9488427/12499-0
00:58:04.966 --> 00:58:06.056
Yes, it's it's done.
ac921801-4673-4330-a447-ea53c9488427/12509-0
00:58:06.066 --> 00:58:09.096
Like the home Valley has been
in, you know, email.
ac921801-4673-4330-a447-ea53c9488427/12512-0
00:58:09.106 --> 00:58:09.676
That's it.
ac921801-4673-4330-a447-ea53c9488427/12518-0
00:58:09.766 --> 00:58:10.896
Now there is more work.
ac921801-4673-4330-a447-ea53c9488427/12531-0
00:58:10.906 --> 00:58:13.886
Yes, it's it's a very good and I
agree with your statement.
ac921801-4673-4330-a447-ea53c9488427/12538-0
00:58:16.066 --> 00:58:17.376
So you're on it.
ac921801-4673-4330-a447-ea53c9488427/12544-0
00:58:17.606 --> 00:58:18.036
Thank you.
ac921801-4673-4330-a447-ea53c9488427/12548-0
00:58:18.756 --> 00:58:19.056
Thanks.
ac921801-4673-4330-a447-ea53c9488427/12560-0
00:58:19.986 --> 00:58:23.066
OK, let's go ahead and thank our
speaker one more time.
ac921801-4673-4330-a447-ea53c9488427/12561-0
00:58:24.886 --> 00:58:25.136
Yes.