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. ac921801-4673-4330-a447-ea53c9488427/813-0 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 00:01:25.986 --> 00:01:30.176 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 00:03:22.176 --> 00:03:25.485 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.