WEBVTT 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/190-0 00:00:03.747 --> 00:00:06.826 So thank you all for attending the earthquake Science Center 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/190-1 00:00:06.826 --> 00:00:07.937 Weekly seminar series. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/196-0 00:00:08.207 --> 00:00:09.757 If you're new, welcome. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/212-0 00:00:09.767 --> 00:00:12.621 If you'd like to be added to our email distribution group, please 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/212-1 00:00:12.621 --> 00:00:13.357 send us an email. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/234-0 00:00:13.787 --> 00:00:17.657 Seminars are recorded and most of the talks are posted on our 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/234-1 00:00:17.657 --> 00:00:20.217 USGS Earthquake Science Center web page. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/258-0 00:00:20.627 --> 00:00:24.232 Closed captioning can be turned on by clicking on the CC icon 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/258-1 00:00:24.232 --> 00:00:26.907 and then the more tab at the top of the page. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/308-0 00:00:27.517 --> 00:00:30.868 Attendees, please mute your mics and turn off your cameras until 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/308-1 00:00:30.868 --> 00:00:33.755 the Q&A session at the end of the talk, submit your 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/308-2 00:00:33.755 --> 00:00:36.848 questions via the chat at any time, or wait to turn on your 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/308-3 00:00:36.848 --> 00:00:39.787 camera and ask your question during the Q&A session. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/311-0 00:00:41.737 --> 00:00:42.077 OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/331-0 00:00:42.087 --> 00:00:46.966 So then a few more announcements for this week, so be sure to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/331-1 00:00:46.966 --> 00:00:48.777 share your suggestions. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/334-0 00:00:48.787 --> 00:00:49.297 Comments. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/337-0 00:00:49.307 --> 00:00:50.037 Ideas. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/349-0 00:00:50.287 --> 00:00:54.347 Comments and ideas in the virtual totally anonymous ESC 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/349-1 00:00:54.347 --> 00:00:54.637 box. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/399-0 00:00:54.847 --> 00:00:59.281 See your email for Shane for the link from Shane for the link and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/399-1 00:00:59.281 --> 00:01:03.715 also of note, we are moving away from passwords so be sure to set 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/399-2 00:01:03.715 --> 00:01:07.477 your a TPIV password today or it will be reset for you. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/412-0 00:01:08.207 --> 00:01:10.471 So the deadline for that is today and thank you for 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/412-1 00:01:10.471 --> 00:01:11.517 resetting your password. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/449-0 00:01:12.897 --> 00:01:17.247 Join us on Thursday, February 29th, which is leap year at 6:00 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/449-1 00:01:17.247 --> 00:01:21.459 PM to view the live stream of the USGS public lecture by our 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/449-2 00:01:21.459 --> 00:01:23.047 very own Sarah McBride. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/461-0 00:01:23.137 --> 00:01:26.397 The talk is titled using communication Science to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/461-1 00:01:26.397 --> 00:01:28.027 communicate USGS science. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/478-0 00:01:28.597 --> 00:01:31.950 See the link in the chat or Google USGS public lecture 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/478-1 00:01:31.950 --> 00:01:32.377 series. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/499-0 00:01:33.447 --> 00:01:36.789 And with that, we will start the recording and I'll pass it over 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/499-1 00:01:36.789 --> 00:01:39.617 to Gene Hardebeck, who will introduce today's speaker. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/501-0 00:01:42.177 --> 00:01:42.357 Yeah. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/511-0 00:01:45.237 --> 00:01:46.147 You're right, you're right. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/514-0 00:01:46.157 --> 00:01:46.907 You're right, you're right. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/519-0 00:01:47.637 --> 00:01:51.027 Do you think there we go? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/524-0 00:01:53.767 --> 00:01:54.297 OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/535-0 00:01:54.697 --> 00:01:59.617 And that's really my pleasure to introduce Peter Shearer. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/609-0 00:02:00.467 --> 00:02:04.963 He is from the Institute of Geophysics and Planetary Physics 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/609-1 00:02:04.963 --> 00:02:09.090 at Scripps Institution of Oceanography at UC San Diego, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/609-2 00:02:09.090 --> 00:02:13.512 where I had the pleasure of doing a postdoc with Peter, and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/609-3 00:02:13.512 --> 00:02:18.008 Peter has a really very broad range of seismology interests, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/609-4 00:02:18.008 --> 00:02:22.726 from global seismology, imaging, imaging of the mantle, through 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/609-5 00:02:22.726 --> 00:02:26.927 to looking at source properties of of small earthquakes. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/645-0 00:02:28.467 --> 00:02:32.776 He has a a very popular introductory introduction to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/645-1 00:02:32.776 --> 00:02:37.654 seismology book and he's won a number of impressive awards, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/645-2 00:02:37.654 --> 00:02:42.370 including the Hu Layman metal and being nominated for the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/645-3 00:02:42.370 --> 00:02:44.647 National Academy of Science. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/649-0 00:02:46.597 --> 00:02:47.427 Back uh. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/657-0 00:02:47.467 --> 00:02:49.287 More than 20 years ago now, when? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/713-0 00:02:49.297 --> 00:02:54.406 When I was a postdoc with Peter, he was one of the first people 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/713-1 00:02:54.406 --> 00:02:59.035 who were developing workflows to deal with big earthquake 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/713-2 00:02:59.035 --> 00:03:03.346 datasets to process buses, basically full catalogs of 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/713-3 00:03:03.346 --> 00:03:07.657 Southern California or other regions to do earthquake 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/713-4 00:03:07.657 --> 00:03:12.207 relocations, and to look at earthquake source processes. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/797-0 00:03:12.737 --> 00:03:17.393 Focal mechanisms, which was what we were working on together and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/797-1 00:03:17.393 --> 00:03:22.121 also importantly stress drop and he developed a technique to take 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/797-2 00:03:22.121 --> 00:03:26.204 a very large data set of small earthquakes and jointly I 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/797-3 00:03:26.204 --> 00:03:30.431 jointly separate out path and side effects from the source 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/797-4 00:03:30.431 --> 00:03:34.013 processes from the source Spectra and that really 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/797-5 00:03:34.013 --> 00:03:38.526 revolutionized how people were thinking about computing stress 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/797-6 00:03:38.526 --> 00:03:40.747 drops for very large data sets. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/835-0 00:03:41.087 --> 00:03:45.502 And so he's gonna be talking today about I I I using those 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/835-1 00:03:45.502 --> 00:03:50.142 sorts of techniques to look at the high frequency energy from 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/835-2 00:03:50.142 --> 00:03:54.708 small to moderate earthquakes and I will turn things over to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/835-3 00:03:54.708 --> 00:03:55.157 Peter. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/839-0 00:03:55.167 --> 00:03:57.367 Thank you and. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/844-0 00:04:02.147 --> 00:04:02.737 OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/848-0 00:04:02.747 --> 00:04:04.767 Well, thank you, Jean. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/851-0 00:04:06.377 --> 00:04:07.137 Uh. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/857-0 00:04:07.377 --> 00:04:09.267 Is that the right angle? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/866-0 00:04:09.277 --> 00:04:11.537 I can't see my good. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/868-0 00:04:11.597 --> 00:04:12.287 OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/923-0 00:04:12.937 --> 00:04:18.460 OK, well, I don't know how many of you may know this, but I 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/923-1 00:04:18.460 --> 00:04:23.983 actually worked at the USGS for on three years right out of 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/923-2 00:04:23.983 --> 00:04:29.783 college, and I worked at first year was field geochemistry and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/923-3 00:04:29.783 --> 00:04:35.766 petrology, and that first summer we did a field work up at Mount 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/923-4 00:04:35.766 --> 00:04:36.227 Hood. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/932-0 00:04:36.237 --> 00:04:41.227 I met Susan Greene, who became my friend. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/965-0 00:04:41.237 --> 00:04:45.988 And then ohh later my wife and she worked in ohh size 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/965-1 00:04:45.988 --> 00:04:51.267 monologist ohh group and and you know she encouraged me to. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/984-0 00:04:51.997 --> 00:04:58.006 Ohh, I'd transfer over to the size Nology group and I worked 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/984-1 00:04:58.006 --> 00:04:59.977 there for two years. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/999-0 00:04:59.987 --> 00:05:05.822 I was trying to find a a dignified photograph of my time 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/999-1 00:05:05.822 --> 00:05:06.437 there. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1010-0 00:05:07.337 --> 00:05:13.117 Was not successful so ohh let me. Hello. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1016-0 00:05:13.177 --> 00:05:14.007 Don't dignified. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1027-0 00:05:14.077 --> 00:05:18.107 Get this to I guess I have two. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1035-0 00:05:18.157 --> 00:05:20.677 I'm doing the arrows which worked before. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1039-0 00:05:22.397 --> 00:05:24.047 What's not working here? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1043-0 00:05:29.767 --> 00:05:31.547 Umm help? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1050-0 00:05:35.417 --> 00:05:36.007 You clicked in. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1052-0 00:05:37.857 --> 00:05:38.127 Yeah. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1058-0 00:05:41.077 --> 00:05:42.117 Ohh oops. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1070-0 00:05:46.967 --> 00:05:48.697 Yeah, I'm not sure what's different. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1077-0 00:05:48.767 --> 00:05:50.697 When I tried it before, it advanced. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1081-0 00:05:55.067 --> 00:05:56.247 OK, OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1086-0 00:05:57.537 --> 00:05:59.707 Uh, try that again. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1101-0 00:05:59.877 --> 00:06:06.687 OK, so here's a photograph that I found, and that's me. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1106-0 00:06:07.037 --> 00:06:07.937 Believe it or not. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1114-0 00:06:07.947 --> 00:06:09.207 Yeah, yeah, I know. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1123-0 00:06:10.077 --> 00:06:14.897 It's very strange to see, and that's Susan. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1145-0 00:06:14.907 --> 00:06:21.551 And then for the youngsters in the crowd, that's a phone and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1145-1 00:06:21.551 --> 00:06:23.947 this is a umm, floppy. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1164-0 00:06:23.957 --> 00:06:29.584 You know, this was before they even had the small floppies or 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1164-1 00:06:29.584 --> 00:06:29.947 any. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1172-0 00:06:29.987 --> 00:06:32.367 Anyway, uh and then. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1179-0 00:06:32.917 --> 00:06:36.557 But when I say umm I I put. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1204-0 00:06:38.787 --> 00:06:43.354 Office in quotes cause we're just a corner of this large 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1204-1 00:06:43.354 --> 00:06:45.277 room, was a shared room. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1237-0 00:06:45.287 --> 00:06:52.300 But the thing that I enjoyed is there was this computer there 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1237-1 00:06:52.300 --> 00:06:59.313 actually it was one of the first desktop computers I guess at 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1237-2 00:06:59.313 --> 00:07:02.707 this time HP was the dominant. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1254-0 00:07:03.067 --> 00:07:10.728 Uh, on OHP, I'm player, I guess in small uh hot scientific 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1254-1 00:07:10.728 --> 00:07:12.027 computers. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1260-0 00:07:12.947 --> 00:07:14.577 So I use that. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1267-0 00:07:16.267 --> 00:07:18.137 OK, well enough of that. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1301-0 00:07:18.467 --> 00:07:23.619 So at the time, you know, these are some of the people that I 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1301-1 00:07:23.619 --> 00:07:28.107 remember, umm, put down the hall and there were more. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1309-0 00:07:28.117 --> 00:07:32.587 And I I see Wayne Thatcher there. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1318-0 00:07:32.597 --> 00:07:35.477 And I realized oops, I forgot to have him there. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1325-0 00:07:37.327 --> 00:07:39.267 Anyway, one of the things you may. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1331-0 00:07:42.017 --> 00:07:43.607 OK, he was he. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1336-0 00:07:43.677 --> 00:07:44.647 He wasn't around. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1338-0 00:07:44.657 --> 00:07:45.167 OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1354-0 00:07:45.457 --> 00:07:49.363 Anyway, so I don't know how many of these names are familiar to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1354-1 00:07:49.363 --> 00:07:49.607 you. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1383-0 00:07:49.617 --> 00:07:53.562 One thing you may notice is they're all male, and I think 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1383-1 00:07:53.562 --> 00:07:57.439 that's one of the welcome changes that we've seen in our 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1383-2 00:07:57.439 --> 00:07:57.847 field. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1397-0 00:07:58.947 --> 00:08:04.087 Uh, anyway, you know these people were all nice to me. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1466-0 00:08:05.737 --> 00:08:10.925 What I want to talk about in order to kind of set up when I 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1466-1 00:08:10.925 --> 00:08:16.201 will be presenting today is there was this uh issue that was 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1466-2 00:08:16.201 --> 00:08:21.649 going around at the time that had to do with observations that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1466-3 00:08:21.649 --> 00:08:26.924 when he looked at high frequency ground accelerations, there 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1466-4 00:08:26.924 --> 00:08:32.458 seemed to be kind of a a maximum frequency at which it would be 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1466-5 00:08:32.458 --> 00:08:33.237 observed. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1468-0 00:08:33.587 --> 00:08:34.367 This was called. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1485-0 00:08:35.977 --> 00:08:42.427 F Max at the time and Tom Hanks who's right there now. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1500-0 00:08:42.797 --> 00:08:46.123 I've wrote a couple of papers about this and are, you know, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1500-1 00:08:46.123 --> 00:08:47.287 extremely well cited. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1522-0 00:08:47.637 --> 00:08:51.508 So you know, this was a, you know, clearly something that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1522-1 00:08:51.508 --> 00:08:52.777 people cared about. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1530-0 00:08:53.547 --> 00:08:56.887 And then there was also this paper. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1543-0 00:08:57.587 --> 00:09:02.407 I'm a few years after that by John Anderson. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1556-0 00:09:02.417 --> 00:09:04.557 And sue Huff and also talked about this. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1562-0 00:09:05.747 --> 00:09:06.697 Umm issue? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1593-0 00:09:06.707 --> 00:09:11.683 And I also have a connection to John because he was my advisor 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1593-1 00:09:11.683 --> 00:09:16.818 my first year at scripts and Sue Hoff was also on the registered 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1593-2 00:09:16.818 --> 00:09:18.477 contemporary of mine. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1611-0 00:09:19.937 --> 00:09:26.802 OK, So what do we mean when we talk about this lack of high 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1611-1 00:09:26.802 --> 00:09:28.747 frequency energy? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1671-0 00:09:29.697 --> 00:09:35.088 So if you have a a a pulse from a umm from an earthquake and you 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1671-1 00:09:35.088 --> 00:09:39.981 compute the Fourier transform and you plot it on a log log 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1671-2 00:09:39.981 --> 00:09:44.709 scale, which is generally the standard when you're doing 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1671-3 00:09:44.709 --> 00:09:49.768 source studies, then you have this flat part that is related 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1671-4 00:09:49.768 --> 00:09:52.257 to on the moment of the event. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1734-0 00:09:52.487 --> 00:09:57.519 And then what we call corner frequency, which is inversely 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1734-1 00:09:57.519 --> 00:10:02.893 related to the pulse width and then it falls off like this and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1734-2 00:10:02.893 --> 00:10:07.755 that's the spectrum in umm displacement and in the broom 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1734-3 00:10:07.755 --> 00:10:13.215 model, which is still kind of on the standard source model this 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1734-4 00:10:13.215 --> 00:10:16.627 fall off is at frequency the minus two. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1769-0 00:10:16.637 --> 00:10:22.497 But of course, when you go to velocity then you multiply by F 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1769-1 00:10:22.497 --> 00:10:28.547 and when you go to acceleration you have another factor of F so 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1769-2 00:10:28.547 --> 00:10:30.627 this thing umm rotate. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1791-0 00:10:30.637 --> 00:10:36.523 So what you then should see in acceleration as it should be 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1791-1 00:10:36.523 --> 00:10:39.957 flat out to umm now I frequencies. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1793-0 00:10:41.507 --> 00:10:42.147 But what? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1805-0 00:10:42.397 --> 00:10:45.487 Umm, I'm at time showed in. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1821-0 00:10:45.497 --> 00:10:49.821 In this case, this is from a very famous record of the San 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1821-1 00:10:49.821 --> 00:10:51.287 Fernando earthquake. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1846-0 00:10:51.437 --> 00:10:55.426 When you look at the acceleration spectrum, you do 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1846-1 00:10:55.426 --> 00:10:59.337 indeed see this flat part, but then it falls off. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1848-0 00:10:59.347 --> 00:11:00.437 In this case at. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1864-0 00:11:02.377 --> 00:11:06.257 Frequencies higher than about a month, 10 to 20 Hertz or so. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1878-0 00:11:09.307 --> 00:11:13.232 And he suggested, you know, there were two possibilities 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1878-1 00:11:13.232 --> 00:11:13.577 here. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1920-0 00:11:13.587 --> 00:11:18.135 One is that it is a source effect and there was some 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1920-1 00:11:18.135 --> 00:11:23.113 speculation that time there might actually be kind of a a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1920-2 00:11:23.113 --> 00:11:28.348 minimum size of earthquake or size of a sparity or something 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1920-3 00:11:28.348 --> 00:11:29.207 like this. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1944-0 00:11:29.217 --> 00:11:34.673 This was a source effect, or it could be due to the site, and in 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1944-1 00:11:34.673 --> 00:11:37.107 particular if you had strong. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1991-0 00:11:37.987 --> 00:11:44.035 Cyber continuation near the surface that could also remove 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1991-1 00:11:44.035 --> 00:11:49.878 the high frequencies and it was that it was at my second 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1991-2 00:11:49.878 --> 00:11:55.516 possibility that the paper by Anderson and though on a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/1991-3 00:11:55.516 --> 00:11:58.797 suggested was what was going on. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2063-0 00:11:58.807 --> 00:12:04.399 So you see in their abstract here they say that the results 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2063-1 00:12:04.399 --> 00:12:10.551 at least the data they looked at were consistent with attenuation 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2063-2 00:12:10.551 --> 00:12:16.423 model in which you know Q is low in the very shallow crust and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2063-3 00:12:16.423 --> 00:12:22.201 that result was supported by some of the borehole seismometer 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2063-4 00:12:22.201 --> 00:12:28.167 results I was involved in one of these with Rick Aster at Anza. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2066-0 00:12:28.657 --> 00:12:29.277 But then also. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2079-0 00:12:31.707 --> 00:12:35.307 Rachel Abercrombie analyzed the Cahone pass. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2101-0 00:12:36.047 --> 00:12:41.652 Ohh, I'd borehole and these results showed that you have 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2101-1 00:12:41.652 --> 00:12:43.717 very low IQ in these. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2113-0 00:12:44.047 --> 00:12:45.217 I'm not. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2172-0 00:12:45.227 --> 00:12:51.502 Your service layer is such a lot of I frequency radiation will be 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2172-1 00:12:51.502 --> 00:12:57.112 removed, but I I think although this seems to be the case, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2172-2 00:12:57.112 --> 00:13:02.817 there's also it's not clear how much of it is due to on the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2172-3 00:13:02.817 --> 00:13:08.617 nurse service queue and how much of it is due to the source. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2176-0 00:13:08.627 --> 00:13:12.167 And I think we still today. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2203-0 00:13:13.477 --> 00:13:20.326 Umm, I need to deal with the fact that there's always gonna 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2203-1 00:13:20.326 --> 00:13:20.897 be a. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2231-0 00:13:20.937 --> 00:13:26.815 How much trade off between how much of high frequencies you 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2231-1 00:13:26.815 --> 00:13:33.183 think are from the source versus those that are removed from the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2231-2 00:13:33.183 --> 00:13:34.457 near surface? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2237-0 00:13:37.467 --> 00:13:38.267 Up structure. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2242-0 00:13:38.277 --> 00:13:39.927 So the model that we're. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2256-0 00:13:40.507 --> 00:13:47.097 Umm, I'm looking at is what we record from the source. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2261-0 00:13:47.787 --> 00:13:48.087 Umm. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2356-0 00:13:48.667 --> 00:13:54.032 Is always gonna have to travel through the nurse service while 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2356-1 00:13:54.032 --> 00:13:59.567 when you have a surface site and that's gonna remove some of the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2356-2 00:13:59.567 --> 00:14:05.187 some of the frequencies from the source that you're going to have 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2356-3 00:14:05.187 --> 00:14:10.552 to put back in if you want to get the true source spectrum and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2356-4 00:14:10.552 --> 00:14:15.917 well, so if we go back to this plot, we just need to know, OK, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2356-5 00:14:15.917 --> 00:14:21.026 if we want the true source spectrum, how much of these high 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2356-6 00:14:21.026 --> 00:14:24.007 frequencies are gonna have to put? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2381-0 00:14:25.917 --> 00:14:32.157 Ohh my back in so now I want to switch gears a bit and as a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2381-1 00:14:32.157 --> 00:14:32.677 gene. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2416-0 00:14:33.607 --> 00:14:37.983 Uh mentioned one of the things I've been involved with is 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2416-1 00:14:37.983 --> 00:14:42.813 trying to do analysis of large datasets to, you know, look at a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2416-2 00:14:42.813 --> 00:14:44.247 lot of earthquakes. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2447-0 00:14:44.257 --> 00:14:49.178 And if you wanna look at a lot of earthquakes, then you have to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2447-1 00:14:49.178 --> 00:14:53.253 look at small earthquakes because they're by far the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2447-2 00:14:53.253 --> 00:14:55.637 dominant number of earthquakes. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2450-0 00:14:55.647 --> 00:14:57.307 And small earthquakes are more. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2456-0 00:14:58.547 --> 00:15:01.617 Challenging to umm. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2474-0 00:15:01.627 --> 00:15:06.452 Constrained because we don't have anything other than the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2474-1 00:15:06.452 --> 00:15:07.367 size grams. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2503-0 00:15:07.477 --> 00:15:12.292 All the information that we know about for small earthquakes is 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2503-1 00:15:12.292 --> 00:15:15.377 gonna have to come from the sized grams. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2524-0 00:15:16.837 --> 00:15:21.797 So there are two kind of key earthquake parameters that we 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2524-1 00:15:21.797 --> 00:15:25.497 think you know, we might be able to obtain. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2541-0 00:15:25.507 --> 00:15:29.387 The first is the moment, and I'm sure all familiar with it is. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2580-0 00:15:30.647 --> 00:15:34.785 I'll proportional to the product of the area times the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2580-1 00:15:34.785 --> 00:15:39.449 displacement, but the moment won't discriminate between where 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2580-2 00:15:39.449 --> 00:15:44.114 where you have large slip on a small fault or small slip on a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2580-3 00:15:44.114 --> 00:15:45.017 large fault. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2593-0 00:15:45.067 --> 00:15:49.777 So we need something else, and that something else is. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2638-0 00:15:50.407 --> 00:15:56.314 I'm mother stress drop, which is the change of stress and the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2638-1 00:15:56.314 --> 00:16:01.840 most common assumption that's made in this modeling is to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2638-2 00:16:01.840 --> 00:16:07.367 assume a circular crack because we don't know any better. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2656-0 00:16:07.737 --> 00:16:14.026 So in that case there is an analytical expression for the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2656-1 00:16:14.026 --> 00:16:15.327 stress drop. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2685-0 00:16:15.337 --> 00:16:21.229 It's not proportional to the displacement over the radius, or 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2685-1 00:16:21.229 --> 00:16:27.216 if you plug in the equation for the moment you can get it into 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2685-2 00:16:27.216 --> 00:16:28.167 this form. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2711-0 00:16:30.517 --> 00:16:36.154 OK, now if we go back to this pulse, the area under the pulse 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2711-1 00:16:36.154 --> 00:16:38.427 is how we get the moment. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2760-0 00:16:38.437 --> 00:16:45.678 This is 0 frequency response and then the pulse width and is 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2760-1 00:16:45.678 --> 00:16:53.394 generally related to the size of the fault or are in the case of 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2760-2 00:16:53.394 --> 00:17:00.161 a circular fault, but because stress drop is ohm up have 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2760-3 00:17:00.161 --> 00:17:04.197 fundamentally a static parameter. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2825-0 00:17:04.207 --> 00:17:09.258 In other words, you know, even if you have a slow slip of that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2825-1 00:17:09.258 --> 00:17:14.149 you you would be able to say that has a stress drop if we're 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2825-2 00:17:14.149 --> 00:17:19.119 gonna get stress drop from the seismic records and we have to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2825-3 00:17:19.119 --> 00:17:24.010 make certain assumptions about the source, we have to have a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2825-4 00:17:24.010 --> 00:17:26.977 model of the dynamics of this store. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2835-0 00:17:26.987 --> 00:17:31.707 So this was started by Jim Brune and others. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2849-0 00:17:32.457 --> 00:17:34.947 Umm, not madariaga. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2875-0 00:17:35.577 --> 00:17:42.057 This is from work that Yoshi Kanako did you know these are 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2875-1 00:17:42.057 --> 00:17:48.648 dynamic rupture simulations, and from that then you can get 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2875-2 00:17:48.648 --> 00:17:49.637 stressed. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2903-0 00:17:49.647 --> 00:17:56.428 Drop from the observations, but it's this rather complicated 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2903-1 00:17:56.428 --> 00:18:03.320 procedure and you have to make assumptions about the dynamics 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2903-2 00:18:03.320 --> 00:18:04.877 of the source. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/2912-0 00:18:05.857 --> 00:18:11.727 However, this all depends on that. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3002-0 00:18:11.917 --> 00:18:17.796 When you measure on the corner frequency from the spectrum that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3002-1 00:18:17.796 --> 00:18:23.583 you've already corrected for Q, in other words, we're assuming 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3002-2 00:18:23.583 --> 00:18:29.370 as a starting point we have the true source spectrum, then you 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3002-3 00:18:29.370 --> 00:18:35.066 also have to have the correct theoretical model which affects 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3002-4 00:18:35.066 --> 00:18:40.945 the OK that you see here umm and also you have to have complete 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3002-5 00:18:40.945 --> 00:18:46.640 averaging over about the focal sphere because the theoretical 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3002-6 00:18:46.640 --> 00:18:51.417 results show that even the case was circular crack. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3007-0 00:18:51.427 --> 00:18:54.047 You have directivity effects. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3023-0 00:18:54.057 --> 00:18:58.858 They're gonna cause the corner frequency to vary as a function 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3023-1 00:18:58.858 --> 00:18:59.697 of azimuth. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3039-0 00:19:00.937 --> 00:19:06.559 OK, so now to kind of jump ahead, we used this approach in 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3039-1 00:19:06.559 --> 00:19:07.417 order to. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3057-0 00:19:10.047 --> 00:19:15.744 Make uh to analyze stress drop for Southern California 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3057-1 00:19:15.744 --> 00:19:16.987 earthquakes. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3082-0 00:19:16.997 --> 00:19:24.991 This is work with Egel Hawks and in 2006 and used a method called 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3082-1 00:19:24.991 --> 00:19:27.777 spectral decomposition. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3150-0 00:19:27.787 --> 00:19:33.352 That Gene talked about and I'll have a little more to say about 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3150-1 00:19:33.352 --> 00:19:38.830 that, but the idea is that we can separate out the source term 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3150-2 00:19:38.830 --> 00:19:44.395 from the path and the site terms in order to isolate the source 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3150-3 00:19:44.395 --> 00:19:49.787 part and then you fit the corner frequencies and umm, you see 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3150-4 00:19:49.787 --> 00:19:53.787 this map of stress drops and this is colored. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3164-0 00:19:53.797 --> 00:19:56.267 You can see the Blues or the higher stress drops. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3170-0 00:19:56.637 --> 00:19:58.487 The Reds are the lower stress drops. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3209-0 00:19:58.497 --> 00:20:03.551 There's a huge amount of scatter that's visible as the hot 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3209-1 00:20:03.551 --> 00:20:08.692 speckling there, but also you can see there's sort of these 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3209-2 00:20:08.692 --> 00:20:13.747 large scale coherent patterns in the average stress drops. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3225-0 00:20:13.757 --> 00:20:16.977 So for example, in the transverse ranges is more blue. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3236-0 00:20:17.377 --> 00:20:18.707 Higher stress drops here. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3248-0 00:20:18.717 --> 00:20:23.487 In the Salton through it's red, more low stress drops. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3266-0 00:20:24.017 --> 00:20:28.755 So you know, you might ask, well, is this real or is it some 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3266-1 00:20:28.755 --> 00:20:29.377 kind of? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3271-0 00:20:30.517 --> 00:20:33.327 Ohh artifact. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3281-0 00:20:33.397 --> 00:20:38.347 Maybe we didn't fully correct for a Q. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3298-0 00:20:38.407 --> 00:20:42.617 So for example, if salt and through we know is more 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3298-1 00:20:42.617 --> 00:20:45.127 attenuating than other regions. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3346-0 00:20:45.357 --> 00:20:50.042 So at that's going to tend to remove the high frequencies and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3346-1 00:20:50.042 --> 00:20:54.879 you know we tried to do a queue correction, but maybe we didn't 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3346-2 00:20:54.879 --> 00:20:59.791 add enough life frequencies back in and that's showing up now as 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3346-3 00:20:59.791 --> 00:21:01.227 lower stress drops. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3364-0 00:21:01.477 --> 00:21:04.147 So the first question we have to ask is this real. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3396-0 00:21:04.377 --> 00:21:09.734 And then on the second one would be OK, if it's a source effect, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3396-1 00:21:09.734 --> 00:21:15.009 why should earthquakes here on average have higher stress drops 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3396-2 00:21:15.009 --> 00:21:17.977 and they do over here or over here? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3401-0 00:21:20.237 --> 00:21:20.587 OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3427-0 00:21:20.597 --> 00:21:25.314 Well, since then there have been some studies that have kind of 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3427-1 00:21:25.314 --> 00:21:29.810 cast doubt on the accuracy or the reliability of stress drop 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3427-2 00:21:29.810 --> 00:21:30.547 estimates. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3462-0 00:21:30.557 --> 00:21:35.786 So I started working with Rachel Abercrombie and number of years 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3462-1 00:21:35.786 --> 00:21:40.774 ago, and we compared the 2006 results to results that she had 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3462-2 00:21:40.774 --> 00:21:43.107 for the Cahone Pass borehole. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3483-0 00:21:43.537 --> 00:21:49.612 And if you plot umm one versus the other, you see here there's 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3483-1 00:21:49.612 --> 00:21:51.637 not very they're not. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3489-0 00:21:51.647 --> 00:21:53.607 Not very much correlation there. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3492-0 00:21:54.797 --> 00:21:55.107 Uh. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3508-0 00:21:56.317 --> 00:22:01.708 And there was a study a few years ago on a on a global 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3508-1 00:22:01.708 --> 00:22:02.297 scale. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3563-0 00:22:02.307 --> 00:22:08.638 I don't have time to talk about this, but a student, my petina 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3563-1 00:22:08.638 --> 00:22:14.768 almond and I worked on on a global stressed up analysis that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3563-2 00:22:14.768 --> 00:22:21.200 was based on a similar spectral decomposition approach and then 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3563-3 00:22:21.200 --> 00:22:26.727 when nearly at all tried to compare their time domain. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3606-0 00:22:27.457 --> 00:22:33.533 No, I'm approach to this, to her results and you just see a just 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3606-1 00:22:33.533 --> 00:22:38.581 a large amount of, umm, scatter there and they argued 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3606-2 00:22:38.581 --> 00:22:44.097 essentially means that you can't trust these stress drops. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3633-0 00:22:44.667 --> 00:22:50.222 And then I think also A cause for concern is that studies, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3633-1 00:22:50.222 --> 00:22:55.777 even the same study often show puzzlingly large changes in 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3633-2 00:22:55.777 --> 00:22:56.907 stress drug. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3695-0 00:22:57.437 --> 00:23:03.933 So this was on a study in Japan that used a similar approach to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3695-1 00:23:03.933 --> 00:23:10.532 spectral decomposition, and you can see, you know, you see these 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3695-2 00:23:10.532 --> 00:23:16.724 not variations, but here in the southwest part of Japan, the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3695-3 00:23:16.724 --> 00:23:22.307 stress drops on average about the factor of 10 larger. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3706-0 00:23:22.737 --> 00:23:27.007 And you know, that may be real, but you know it seems. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3713-0 00:23:28.817 --> 00:23:31.247 Umm, somewhat surprising. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3727-0 00:23:31.257 --> 00:23:36.751 I think that you would have such a large change, you know, along 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3727-1 00:23:36.751 --> 00:23:37.597 the Japan. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3731-0 00:23:38.897 --> 00:23:39.657 Uh. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3746-0 00:23:39.697 --> 00:23:46.733 Chain like this and then some work that Daniel Trugman did 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3746-1 00:23:46.733 --> 00:23:47.687 with me. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3787-0 00:23:47.777 --> 00:23:51.992 A few years ago in Southern California, we were trying to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3787-1 00:23:51.992 --> 00:23:56.497 follow up on the 2006 study by looking in more detail at some 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3787-2 00:23:56.497 --> 00:24:00.567 regions and doing a separate analysis of those regions. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3806-0 00:24:00.577 --> 00:24:07.654 And two of the reasons we looked at were aftershocks of Landers 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3806-1 00:24:07.654 --> 00:24:09.977 and mind earthquakes. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3840-0 00:24:09.987 --> 00:24:13.926 These were large magnitude 7 earthquakes, but in the Mojave 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3840-1 00:24:13.926 --> 00:24:17.865 and the thing that someone surprising is that well, I mean, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3840-2 00:24:17.865 --> 00:24:19.507 there's a lot of scatter. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3876-0 00:24:19.517 --> 00:24:23.297 You always see a lot of scatter in these stress drop studies, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3876-1 00:24:23.297 --> 00:24:26.955 but when you compare Landers that your mind there's about a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3876-2 00:24:26.955 --> 00:24:28.297 factor of four change. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3891-0 00:24:28.467 --> 00:24:31.974 And again, that seems kind of surprising because these 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3891-1 00:24:31.974 --> 00:24:34.397 earthquakes, you know, were both out. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3900-0 00:24:34.407 --> 00:24:36.057 You know, they're not that far away. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3902-0 00:24:36.347 --> 00:24:37.147 You'd think that. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3931-0 00:24:39.247 --> 00:24:44.531 Have the tectonics should be about the same, so why would 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3931-1 00:24:44.531 --> 00:24:49.087 there be a a factor for change in the just drops? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3946-0 00:24:49.097 --> 00:24:55.165 OK, so that umm motivates kind of a reexamination of this 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3946-1 00:24:55.165 --> 00:24:56.107 question. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3954-0 00:24:56.117 --> 00:24:59.427 What can we believe in these? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3972-0 00:24:59.437 --> 00:25:05.764 Stress drop estimates and how can we make progress and we have 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/3972-1 00:25:05.764 --> 00:25:06.467 to, uh. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4004-0 00:25:06.667 --> 00:25:12.620 Recognize that our, umm, my theories always have these nice 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4004-1 00:25:12.620 --> 00:25:18.970 smooth looking uh Spectra, but the actual observations are much 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4004-2 00:25:18.970 --> 00:25:23.237 more complicated that show irregularities. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4017-0 00:25:23.297 --> 00:25:26.397 Is the main thing, however that I want to. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4025-0 00:25:28.277 --> 00:25:28.767 Umm. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4032-0 00:25:28.857 --> 00:25:31.367 Emphasize is this queue. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4064-0 00:25:31.377 --> 00:25:37.777 Corrections are tricky to make, so if we think about all of the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4064-1 00:25:37.777 --> 00:25:44.077 things that could cause scatter in stress drop estimates, I've 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4064-2 00:25:44.077 --> 00:25:46.577 listed some of them here. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4077-0 00:25:46.707 --> 00:25:51.837 I don't have time on a month to talk about them. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4080-0 00:25:51.847 --> 00:25:52.287 All. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4085-0 00:25:53.127 --> 00:25:56.677 Uh the ohh what? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4111-0 00:25:56.687 --> 00:26:00.992 What we've seen is that all of these things are either not that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4111-1 00:26:00.992 --> 00:26:03.817 important or can be easily accounted for. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4119-0 00:26:03.907 --> 00:26:06.687 Except for this, I'm final one. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4151-0 00:26:06.697 --> 00:26:12.735 These uncertainties in the queue corrections that uh to some 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4151-1 00:26:12.735 --> 00:26:18.774 extent it goes back to these these concerns about the source 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4151-2 00:26:18.774 --> 00:26:22.437 of F Max that I talked about before. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4180-0 00:26:22.877 --> 00:26:28.103 So just to remind us, we need to have this path correction if 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4180-1 00:26:28.103 --> 00:26:32.487 we're going to contain the true source of spectrum. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4208-0 00:26:32.817 --> 00:26:39.286 It's not hard to solve for Q models for the mid to lower 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4208-1 00:26:39.286 --> 00:26:45.188 crust, but it's hard in the absence of boreholes as 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4208-2 00:26:45.188 --> 00:26:46.437 manometers. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4225-0 00:26:46.447 --> 00:26:52.816 To resolve that, I'm trade off between the nurse service side 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4225-1 00:26:52.816 --> 00:26:55.077 effect and the source. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4243-0 00:26:55.807 --> 00:27:00.821 So are these ohm path corrections are often performed 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4243-1 00:27:00.821 --> 00:27:02.307 by what we call. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4247-0 00:27:07.717 --> 00:27:08.387 Stuttering. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4283-0 00:27:08.397 --> 00:27:13.788 Here, try to relax and M empirical greens functions and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4283-1 00:27:13.788 --> 00:27:19.564 just to remind us, they're called empirical because they're 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4283-2 00:27:19.564 --> 00:27:25.437 not really based on on theory or just from the observations. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4307-0 00:27:25.447 --> 00:27:29.211 And then the Greens function is what we use in seismology to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4307-1 00:27:29.211 --> 00:27:32.297 talk about the source receiver response function. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4334-0 00:27:33.117 --> 00:27:38.251 So the idea is that when you have a small quake that's near a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4334-1 00:27:38.251 --> 00:27:41.647 large quake, then we can do first order. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4366-0 00:27:41.657 --> 00:27:47.906 Just assume that they're near enough that the path correction 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4366-1 00:27:47.906 --> 00:27:53.047 is the same, and it's sort of it's idealized form. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4415-0 00:27:53.057 --> 00:27:58.730 A small cake would be small enough that it's actually flat 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4415-1 00:27:58.730 --> 00:28:04.308 over the band that we're concerned with, and if that were 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4415-2 00:28:04.308 --> 00:28:10.174 the case, then all you'd have to do is umm umm, subtract the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4415-3 00:28:10.174 --> 00:28:15.367 small event response from the A large event response. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4433-0 00:28:15.577 --> 00:28:19.519 So this is what we observe, but we know the small one should be 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4433-1 00:28:19.519 --> 00:28:19.827 flat. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4453-0 00:28:19.837 --> 00:28:24.710 So we move that up and then we also move that up and then we 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4453-1 00:28:24.710 --> 00:28:27.107 should obtain the true source. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4502-0 00:28:28.607 --> 00:28:32.176 The problem with this in practice is small events are 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4502-1 00:28:32.176 --> 00:28:36.208 never small enough that you can assume that they're flat, so 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4502-2 00:28:36.208 --> 00:28:40.108 then it turns out that the assumptions that you make about 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4502-3 00:28:40.108 --> 00:28:44.207 the small events are going to have an effect on what you are. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4506-0 00:28:44.797 --> 00:28:46.007 Uh, uh. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4551-0 00:28:46.237 --> 00:28:52.024 What you obtained for the large events, so the work that I 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4551-1 00:28:52.024 --> 00:28:57.910 started with Umm Rachel a few years ago, we thought, OK, we 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4551-2 00:28:57.910 --> 00:29:04.090 really need to get in and see all the steps to understand what 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4551-3 00:29:04.090 --> 00:29:05.267 is going on. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4579-0 00:29:05.277 --> 00:29:09.841 And wanted to compare the spectral decomposition that I'm 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4579-1 00:29:09.841 --> 00:29:14.564 more familiar with with the spectral ratio method that that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4579-2 00:29:14.564 --> 00:29:15.587 she had used. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4596-0 00:29:15.597 --> 00:29:22.458 More so, we wanted to use a common data set in order to do 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4596-1 00:29:22.458 --> 00:29:24.087 this analysis. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4605-0 00:29:24.727 --> 00:29:27.427 So we chose a dense aftershock. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4618-0 00:29:27.597 --> 00:29:32.097 Ohm out cluster the 99 two Landers earthquake. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4647-0 00:29:32.107 --> 00:29:38.652 So there were over 3000 of these aftershocks and this 6 kilometer 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4647-1 00:29:38.652 --> 00:29:41.727 sided cube and these are small. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4675-0 00:29:42.077 --> 00:29:48.458 Generally, having magnitudes of 0.5 to 3.5, you can see you know 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4675-1 00:29:48.458 --> 00:29:54.447 the little Red Square there among the stations that we used. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4701-0 00:29:54.517 --> 00:30:00.475 So we assume that it was small enough that we could, ah, assume 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4701-1 00:30:00.475 --> 00:30:05.037 that the path correction should all be the same. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4745-0 00:30:05.547 --> 00:30:09.414 OK, so the first method is a spectral decomposition, and the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4745-1 00:30:09.414 --> 00:30:12.901 idea here is when you have a large data set where each 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4745-2 00:30:12.901 --> 00:30:16.768 earthquake is recorded by a lot of stations and each station 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4745-3 00:30:16.768 --> 00:30:18.607 records a lot of earthquakes. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4765-0 00:30:18.907 --> 00:30:23.840 Then there's redundancy in the system that should allow one to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4765-1 00:30:23.840 --> 00:30:27.207 isolate a source spectrum from a receiver. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4777-0 00:30:27.917 --> 00:30:30.927 Umm, a pop station term essentially. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4797-0 00:30:30.937 --> 00:30:38.387 Then I travel time dependent term to account for Q and it is 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4797-1 00:30:38.387 --> 00:30:41.807 a hot, completely empirical. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4810-0 00:30:41.817 --> 00:30:45.627 You know there's no physics inner goal. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4815-0 00:30:45.637 --> 00:30:46.977 It's just a way to try to. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4861-0 00:30:47.817 --> 00:30:52.349 Umm, I'll try to isolate the source spectrum from all the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4861-1 00:30:52.349 --> 00:30:56.959 other effects, but you can see right away that there's a a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4861-2 00:30:56.959 --> 00:31:01.725 fundamental ambiguity in that you could add something to the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4861-3 00:31:01.725 --> 00:31:05.007 source spectrum and subtract it from the. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4884-0 00:31:07.387 --> 00:31:12.301 Receiver spectrum, you have exactly the same answer, so it's 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4884-1 00:31:12.301 --> 00:31:15.927 really only a measure of the relative chain. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4888-0 00:31:16.997 --> 00:31:17.757 Excuse me a second. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4896-0 00:31:23.547 --> 00:31:24.287 So the source. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4903-0 00:31:24.637 --> 00:31:28.007 Well, I'm Spectra that we obtain or only. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4942-0 00:31:29.207 --> 00:31:35.292 Relative and then we need to have some way to calibrate this 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4942-1 00:31:35.292 --> 00:31:41.476 to get the true shape of these source Spectra in the way that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4942-2 00:31:41.476 --> 00:31:45.267 we did this in the 2006 study was to. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4986-0 00:31:46.817 --> 00:31:52.686 Stack the raw source terms by moment and you can see that they 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4986-1 00:31:52.686 --> 00:31:58.277 don't look like what we think they should look like in that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/4986-2 00:31:58.277 --> 00:32:02.097 the small ones are not flat, they go up. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5053-0 00:32:02.167 --> 00:32:07.434 So we do then is we solve for this, what we call an empirical 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5053-1 00:32:07.434 --> 00:32:12.957 correction spectrum or ECS shown as the red curve such that when 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5053-2 00:32:12.957 --> 00:32:17.885 we subtract it from always and we're going to remove that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5053-3 00:32:17.885 --> 00:32:22.898 ambiguity is the idea and we then obtain a good fit to the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5053-4 00:32:22.898 --> 00:32:24.937 model about predictions. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5092-0 00:32:25.187 --> 00:32:30.215 So for the 2006 study, we assumed the model of a brune on 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5092-1 00:32:30.215 --> 00:32:35.156 spectrum that was on self similar by self similar I mean 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5092-2 00:32:35.156 --> 00:32:39.317 things to scale up and down with magnitude and. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5098-0 00:32:40.937 --> 00:32:42.227 Uh, such that? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5105-0 00:32:42.647 --> 00:32:45.937 The stress drop is constant. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5119-0 00:32:46.007 --> 00:32:50.497 That's one of the Sumption that goes into self similarity. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5139-0 00:32:50.767 --> 00:32:56.251 So you know, when we got a fit like this, you know, we thought, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5139-1 00:32:56.251 --> 00:32:58.737 yeah, that looks pretty good. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5145-0 00:32:58.827 --> 00:33:00.757 So we're done, right? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5155-0 00:33:00.767 --> 00:33:03.717 I mean we we have a model and it works. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5181-0 00:33:05.507 --> 00:33:10.948 But what we found from the Landers study is that there's 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5181-1 00:33:10.948 --> 00:33:15.817 not just one model that will fit the those curves. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5208-0 00:33:16.287 --> 00:33:22.841 So here there's a non self similar broom fit in which 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5208-1 00:33:22.841 --> 00:33:27.697 stress drop grows linearly with moment. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5244-0 00:33:27.797 --> 00:33:32.921 If you force the broom fit to be self similar, you don't do as 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5244-1 00:33:32.921 --> 00:33:37.720 well and you might say, OK, well, you know, there's enough 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5244-2 00:33:37.720 --> 00:33:41.787 of a misfit here that we would reject that model. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5271-0 00:33:42.157 --> 00:33:45.847 But it's not hard to come up with self similar model that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5271-1 00:33:45.847 --> 00:33:50.047 fits if you're willing to change the high frequency falloff rate. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5385-0 00:33:50.157 --> 00:33:55.471 So in the broom model, it's two and in 2006 we forced it to be 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5385-1 00:33:55.471 --> 00:34:00.617 2, but in fact, you know, some models suggest that you might 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5385-2 00:34:00.617 --> 00:34:05.678 have a lower hyperemesis fall over rate if you do that, you 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5385-3 00:34:05.678 --> 00:34:11.077 can preserve self similarity or if you want your stress drop to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5385-4 00:34:11.077 --> 00:34:16.475 be lower, you can force things to be lower you or you can force 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5385-5 00:34:16.475 --> 00:34:21.790 things to be higher, the stress drop you assume for the OR the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5385-6 00:34:21.790 --> 00:34:26.513 you force for the small earthquakes will tend to affect 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5385-7 00:34:26.513 --> 00:34:30.647 the degree of scaling with moment that you have. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5400-0 00:34:30.657 --> 00:34:36.577 But the problem is if you really want to if if you allow both. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5411-0 00:34:37.237 --> 00:34:39.327 Well, I'm all of these things. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5423-0 00:34:39.337 --> 00:34:43.059 In other words, nothing absolute stress drop of the smallest 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5423-1 00:34:43.059 --> 00:34:43.487 events. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5432-0 00:34:45.657 --> 00:34:47.307 Whether you have non. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5434-0 00:34:47.567 --> 00:34:47.837 No. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5469-0 00:34:48.527 --> 00:34:51.489 I'm so similar scaling whether it's with her stressed her up, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5469-1 00:34:51.489 --> 00:34:54.548 rose with moment and hypergamy fall off right, they're just too 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5469-2 00:34:54.548 --> 00:34:54.787 many. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5488-0 00:34:55.387 --> 00:35:01.153 Uh, I'm free parameters and there's too many ways that you 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5488-1 00:35:01.153 --> 00:35:03.597 can get a reasonable fit. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5506-0 00:35:05.107 --> 00:35:12.617 However, you can still trust the relative changes in stress drop. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5515-0 00:35:12.667 --> 00:35:13.997 Now there is a high stress drop. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5565-0 00:35:14.007 --> 00:35:18.398 Reunions still are, even though you don't know on the absolute 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5565-1 00:35:18.398 --> 00:35:22.790 level of stress drop, there's still showing that those regions 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5565-2 00:35:22.790 --> 00:35:26.275 are radiating more high frequency energy than the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5565-3 00:35:26.275 --> 00:35:30.109 regions that have the lower stress drubs ohgi doing on 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5565-4 00:35:30.109 --> 00:35:30.737 tomorrow. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5568-0 00:35:32.367 --> 00:35:32.937 OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5577-0 00:35:32.947 --> 00:35:38.187 So then the second approach is this hot spectral. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5638-0 00:35:40.477 --> 00:35:45.833 Racial approach and here for each of the target events you 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5638-1 00:35:45.833 --> 00:35:50.553 find a set of smaller earthquakes and then you take 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5638-2 00:35:50.553 --> 00:35:56.545 the spectral ratio between those and then you will simultaneously 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5638-3 00:35:56.545 --> 00:36:01.356 then fit for the corner frequency of the larger vent 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5638-4 00:36:01.356 --> 00:36:04.897 that you were primarily interested in. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5673-0 00:36:05.147 --> 00:36:12.851 And the smaller in that on the problem here is that for real 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5673-1 00:36:12.851 --> 00:36:20.430 data examples that the fit for the small event will have an 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5673-2 00:36:20.430 --> 00:36:24.977 effect on the fit to larger amount. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5689-0 00:36:24.987 --> 00:36:28.825 In other words, you can't assume these fits are completely 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5689-1 00:36:28.825 --> 00:36:30.517 independent of each other. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5707-0 00:36:30.967 --> 00:36:41.003 So in order to show this, we compared the spectral ratios for 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5707-1 00:36:41.003 --> 00:36:44.727 in this case, uh these. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5709-0 00:36:46.877 --> 00:36:47.267 Umm. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5765-0 00:36:47.937 --> 00:36:52.686 A larger target events almost magnitude 3, and we looked at 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5765-1 00:36:52.686 --> 00:36:57.278 the smaller events are being used for the EDF and what we 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5765-2 00:36:57.278 --> 00:37:02.028 found is that the assumption of the corner frequency of the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5765-3 00:37:02.028 --> 00:37:06.619 smaller events would actually change when you changed the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5765-4 00:37:06.619 --> 00:37:07.807 target of that. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5794-0 00:37:08.097 --> 00:37:14.910 So the spectral ratio method is not self consistent in that for 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5794-1 00:37:14.910 --> 00:37:21.297 each target event it's allowing the EGF to change on words. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5802-0 00:37:21.917 --> 00:37:23.187 Uh, my not. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5874-0 00:37:23.197 --> 00:37:29.182 The path correction is not the same, which means that you can 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5874-1 00:37:29.182 --> 00:37:34.684 no longer than trust even the relative stress drops that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5874-2 00:37:34.684 --> 00:37:40.284 you're obtaining from the spectral operatio method, and I 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5874-3 00:37:40.284 --> 00:37:46.462 think and that's what I've said here, that you get this bias by 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5874-4 00:37:46.462 --> 00:37:51.964 the fact that you're not enforcing the smaller events to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5874-5 00:37:51.964 --> 00:37:55.247 have the same corner frequencies. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5884-0 00:37:56.707 --> 00:38:00.977 OK, So what is the takeaway from this? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5933-0 00:38:00.987 --> 00:38:07.243 It's that they're all of these trade offs that are going on 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5933-1 00:38:07.243 --> 00:38:13.395 that are essentially preventing us from getting in uh from 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5933-2 00:38:13.395 --> 00:38:19.860 knowing for sure what the true source spectrum is and that in 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5933-3 00:38:19.860 --> 00:38:24.657 any of these studies you can trust on the on. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5966-0 00:38:24.927 --> 00:38:31.368 Relative variations on much more than absolute variations, and I 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5966-1 00:38:31.368 --> 00:38:37.017 don't think I mean I myself, I'm certainly did not fully 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/5966-2 00:38:37.017 --> 00:38:40.387 appreciate all of these problems. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6023-0 00:38:41.737 --> 00:38:47.363 Umm, so there must be a better approach and that motivates what 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6023-1 00:38:47.363 --> 00:38:53.078 we started doing a few years ago and that's to say, OK, well, if 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6023-2 00:38:53.078 --> 00:38:58.440 the problem is that the small earthquake stress drops or I'm 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6023-3 00:38:58.440 --> 00:39:03.100 I'm quite frequencies are unconstrained, let's add a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6023-4 00:39:03.100 --> 00:39:04.067 constraint. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6065-0 00:39:04.357 --> 00:39:09.630 So we force the broom corner frequency of the small in this 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6065-1 00:39:09.630 --> 00:39:14.376 case on magnitude 1 1/2 earthquakes we just say we're 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6065-2 00:39:14.376 --> 00:39:18.947 going to force the corner frequency to be 30 Hertz. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6076-0 00:39:19.147 --> 00:39:24.507 So in this way that's going to umm umm I'm directly. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6100-0 00:39:25.907 --> 00:39:31.940 Ohh fix the in the spider decomposition approach this ECS 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6100-1 00:39:31.940 --> 00:39:32.877 function. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6114-0 00:39:33.347 --> 00:39:38.732 So we've by, umm, essentially, we're gonna force all the men to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6114-1 00:39:38.732 --> 00:39:40.667 1 1/2 to honor average. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6118-0 00:39:40.977 --> 00:39:42.007 Look the same. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6140-0 00:39:42.437 --> 00:39:47.494 So we're going to try to therefore remove all the spatial 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6140-1 00:39:47.494 --> 00:39:48.977 variations there. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6169-0 00:39:50.097 --> 00:39:56.772 However, that then ensures that if we see variations in larger 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6169-1 00:39:56.772 --> 00:40:02.917 events that those are real because in some sense we tried 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6169-2 00:40:02.917 --> 00:40:04.507 to remove them. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6184-0 00:40:04.597 --> 00:40:09.187 So if they're still there, then those must be real variations. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6203-0 00:40:09.197 --> 00:40:14.963 So why did we choose to set the corner frequency to umm, a pop 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6203-1 00:40:14.963 --> 00:40:15.787 30 Hertz? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6249-0 00:40:15.797 --> 00:40:20.916 Well, this is a somewhat arbitrary choice, but it is all 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6249-1 00:40:20.916 --> 00:40:26.484 my, umm up based on results from the Cahone pass moral, which 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6249-2 00:40:26.484 --> 00:40:31.424 provides some of the best constraints on what the true 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6249-3 00:40:31.424 --> 00:40:34.657 source spectrum of small events is. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6271-0 00:40:34.987 --> 00:40:40.228 And you know, if we were to change this, it would have the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6271-1 00:40:40.228 --> 00:40:44.847 effect of moving all the resolving stress drop but. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6293-0 00:40:47.417 --> 00:40:53.909 I'm estimates down or up, but the relative ohh result should 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6293-1 00:40:53.909 --> 00:40:55.187 still be OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6297-0 00:40:57.167 --> 00:40:57.637 OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6308-0 00:40:57.647 --> 00:41:02.857 So I'll kind of skip over this because it's not. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6361-0 00:41:04.187 --> 00:41:10.184 Complicated to explain, but the idea is that we have the true or 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6361-1 00:41:10.184 --> 00:41:16.182 the source term that we want to resolve and we find all of these 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6361-2 00:41:16.182 --> 00:41:22.179 small events that are nearby and we see that they look like this 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6361-3 00:41:22.179 --> 00:41:26.147 and we say OK, they should look like this. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6377-0 00:41:26.927 --> 00:41:28.897 So we're going to force them all to be that. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6399-0 00:41:28.907 --> 00:41:33.734 And the difference between those is then the ECS function which 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6399-1 00:41:33.734 --> 00:41:36.827 has some degree of irregularities in it. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6435-0 00:41:36.837 --> 00:41:41.828 So we smooth it and then when we subtract that from the the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6435-1 00:41:41.828 --> 00:41:46.735 source term, we get the ECS corrected source term which we 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6435-2 00:41:46.735 --> 00:41:49.647 can then fit for the conferencing. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6470-0 00:41:50.117 --> 00:41:56.672 OK, so to get back to our map, what I'm showing is the results 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6470-1 00:41:56.672 --> 00:42:03.020 of this now applied, but we're only looking at the magnitude 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6470-2 00:42:03.020 --> 00:42:04.477 more than two. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6498-0 00:42:04.567 --> 00:42:08.232 Well, if you look at magnitude 1 1/2, you're not gonna see any 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6498-1 00:42:08.232 --> 00:42:11.257 spatial variations because we've removed all those. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6510-0 00:42:11.637 --> 00:42:16.087 You can see, however, what we saw before is still there. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6539-0 00:42:16.217 --> 00:42:20.519 This uh region here in the transverse ranges has higher 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6539-1 00:42:20.519 --> 00:42:25.436 stress drops this region and the salt and drop has lower stress 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6539-2 00:42:25.436 --> 00:42:25.897 drops. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6586-0 00:42:25.967 --> 00:42:32.621 So we know now that this is a true source effect because it's 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6586-1 00:42:32.621 --> 00:42:39.489 based on the relative shapes of the Spectra of the large events 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6586-2 00:42:39.489 --> 00:42:46.143 compared to the magnitude 11.5 of that's so there's no way to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6586-3 00:42:46.143 --> 00:42:47.217 to change. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6596-0 00:42:48.137 --> 00:42:52.237 The Q model in order to remove this. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6633-0 00:42:54.777 --> 00:43:01.072 Uh, we see in our uh latest results, that stress drops are 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6633-1 00:43:01.072 --> 00:43:06.407 on average more than they were in the 2006 study. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6645-0 00:43:06.937 --> 00:43:11.487 They are flat with magnitude up to about 3:00. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6652-0 00:43:11.737 --> 00:43:13.937 And then there's this growth. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6686-0 00:43:15.027 --> 00:43:21.228 I the question as to whether stress drop may grow with ohm 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6686-1 00:43:21.228 --> 00:43:27.954 moment has been a long standing controversy in seismology, so I 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6686-2 00:43:27.954 --> 00:43:30.477 don't have all the time. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6698-0 00:43:32.467 --> 00:43:35.477 Talk about, but I wanna say two things. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6752-0 00:43:35.487 --> 00:43:41.609 One is that that this trend, if it's real, it you can't continue 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6752-1 00:43:41.609 --> 00:43:47.449 it because then you'll get to stress drops that are too large 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6752-2 00:43:47.449 --> 00:43:53.477 and we know for the Ohm's larger earthquakes where we have true 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6752-3 00:43:53.477 --> 00:43:57.057 constraints on on there's just drops. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6759-0 00:43:57.067 --> 00:44:00.467 We know that they don't get that large. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6813-0 00:44:01.167 --> 00:44:07.442 Umm, but the other thing to keep in mind is that this trend is 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6813-1 00:44:07.442 --> 00:44:13.618 also based on the broom model, which assumes a high frequency 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6813-2 00:44:13.618 --> 00:44:19.793 follow rate of two and it's easy to come up with results that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6813-3 00:44:19.793 --> 00:44:23.977 show it being flat out to larger moments. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6863-0 00:44:23.987 --> 00:44:29.923 If you allow the high frequency fall off rate to be lower than 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6863-1 00:44:29.923 --> 00:44:35.482 two, So what not on the data seem to be saying is that the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6863-2 00:44:35.482 --> 00:44:41.229 larger events radiate more high frequency energy than a self 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6863-3 00:44:41.229 --> 00:44:44.527 similar room model would per dict. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6913-0 00:44:44.587 --> 00:44:49.230 So if you want to retain the broom model if the drop the self 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6913-1 00:44:49.230 --> 00:44:53.648 similarity, if you want to retain the self similarity then 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6913-2 00:44:53.648 --> 00:44:58.291 you have to drop the broom model and allow the high frequency 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6913-3 00:44:58.291 --> 00:45:01.437 falloff freight to be something like 1.7. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6944-0 00:45:04.117 --> 00:45:09.302 OK, now I've been using the term stress drop here, but we also 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6944-1 00:45:09.302 --> 00:45:12.347 should keep in mind that dress drop. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6966-0 00:45:12.357 --> 00:45:17.740 These numbers are very model dependent and I wanted to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6966-1 00:45:17.740 --> 00:45:22.047 highlight this old ohm Jill, Jill Atkinson. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6971-0 00:45:24.187 --> 00:45:24.567 Umm. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6982-0 00:45:25.427 --> 00:45:29.527 Article where she says don't call it. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/6988-0 00:45:32.817 --> 00:45:33.927 Stress drop. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7010-0 00:45:34.007 --> 00:45:40.217 She has this great up a quote here, but she does say it's 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7010-1 00:45:40.217 --> 00:45:40.967 manual. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7045-0 00:45:40.977 --> 00:45:46.030 In recent years, has been as a measure of the strength of the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7045-1 00:45:46.030 --> 00:45:50.921 high frequency radiation, and I think that's sort of key to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7045-2 00:45:50.921 --> 00:45:52.307 think about this. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7092-0 00:45:52.717 --> 00:45:58.225 If you want to get closer to the observations, the observations 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7092-1 00:45:58.225 --> 00:46:02.959 really are about the relative amount of high frequency 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7092-2 00:46:02.959 --> 00:46:08.123 radiation, and then we have to make a whole lot of modeling 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7092-3 00:46:08.123 --> 00:46:12.427 assumptions to some translate that into she's 12. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7103-0 00:46:12.577 --> 00:46:14.517 So they go back to this map. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7136-0 00:46:14.657 --> 00:46:22.327 It's really a map of the high frequency radiation and that is 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7136-1 00:46:22.327 --> 00:46:27.647 why I like to use blue for uh not ohm ohm. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7178-0 00:46:28.117 --> 00:46:32.447 Hello, High stressed warrants and red for the low stress drops 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7178-1 00:46:32.447 --> 00:46:36.709 because blue of course has more of a high frequency radiation 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7178-2 00:46:36.709 --> 00:46:39.527 and red as that's the average radiation. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7192-0 00:46:39.617 --> 00:46:43.417 So those of you who do stress drop studies, you should be 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7192-1 00:46:43.417 --> 00:46:44.597 using this scheme. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7226-0 00:46:44.637 --> 00:46:49.585 It doesn't seem to be the case for most people seem to like to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7226-1 00:46:49.585 --> 00:46:53.749 use red for high stress throughout because it's more 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7226-2 00:46:53.749 --> 00:46:55.477 exciting or something. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7229-0 00:46:55.487 --> 00:46:56.027 I don't know. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7253-0 00:46:56.137 --> 00:47:01.301 Anyway, blue means more high frequency energy, so the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7253-1 00:47:01.301 --> 00:47:07.517 fundamental observation here is that earthquakes are the same on 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7253-2 00:47:07.517 --> 00:47:08.187 moment. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7271-0 00:47:08.587 --> 00:47:12.997 I'm very a lot in their high frequency radiation and so on. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7280-0 00:47:13.227 --> 00:47:14.177 You know these. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7286-0 00:47:15.127 --> 00:47:21.017 There's scatter in that, but there are real coherent spatial. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7294-0 00:47:21.777 --> 00:47:23.987 I'm I'm variations. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7299-0 00:47:24.337 --> 00:47:27.287 So what does that mean? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7331-0 00:47:27.697 --> 00:47:31.120 So for talking about different types of radiation, well, you 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7331-1 00:47:31.120 --> 00:47:34.487 know, it could indeed be due to the earthquake stress drop. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7351-0 00:47:34.577 --> 00:47:39.550 It could just be that the rupture speed changes one of the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7351-1 00:47:39.550 --> 00:47:43.427 assumptions that goes into ohm ohm ohm month. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7392-0 00:47:45.877 --> 00:47:50.497 On the K factor, when you're going from corner brings this 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7392-1 00:47:50.497 --> 00:47:55.351 stress drop involves the rupture speed, so lower stress drops 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7392-2 00:47:55.351 --> 00:47:58.327 could just be a lower rupture speeds. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7416-0 00:47:58.777 --> 00:48:03.538 They're also just could be that some of that the the ones that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7416-1 00:48:03.538 --> 00:48:07.317 radiate more high frequency are more complicated. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7418-0 00:48:08.217 --> 00:48:08.807 Ruptures. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7443-0 00:48:10.377 --> 00:48:15.536 What could be the cause of a spatial variations or sort of 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7443-1 00:48:15.536 --> 00:48:17.897 two main uh, I'll thoughts. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7472-0 00:48:17.907 --> 00:48:21.996 I guess one is it has something to do with all the rock, in 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7472-1 00:48:21.996 --> 00:48:26.017 which case that what you see isn't gonna evolve with time. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7527-0 00:48:26.027 --> 00:48:28.177 Or it could have something to do with the local. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7533-0 00:48:28.827 --> 00:48:34.467 Ohh, I'd stress state in which case that you might see things 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7533-1 00:48:34.467 --> 00:48:39.925 change in response to large earthquakes, just like the work 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7533-2 00:48:39.925 --> 00:48:43.837 gene is done to look at the change in ohm. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7557-0 00:48:44.927 --> 00:48:49.769 How focal mechanisms responding to changes in stress due to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7557-1 00:48:49.769 --> 00:48:52.917 larger earthquakes and one small clue? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7599-0 00:48:52.927 --> 00:48:57.642 This is also work that Patino Almond did, looking at Parkfield 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7599-1 00:48:57.642 --> 00:49:02.506 earthquakes that seemed to show that the areas of high frequency 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7599-2 00:49:02.506 --> 00:49:04.527 radiation that we're there. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7645-0 00:49:04.957 --> 00:49:09.995 Umm prior to the magnitude 6 part filter earthquake, we're 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7645-1 00:49:09.995 --> 00:49:15.119 still there following and parks and is one of the few areas 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7645-2 00:49:15.119 --> 00:49:19.901 where we have a lot of seismicity both before and after 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7645-3 00:49:19.901 --> 00:49:21.097 the main shot. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7678-0 00:49:23.277 --> 00:49:29.089 OK, so this is my last slide and basically all of these analysis 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7678-1 00:49:29.089 --> 00:49:33.740 have large uncertainties, at least for the absolute 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7678-2 00:49:33.740 --> 00:49:37.317 earthquake to pop, pop, pop properties. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7691-0 00:49:37.687 --> 00:49:41.507 We think now the most reliable way to do this is just to fix. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7726-0 00:49:42.997 --> 00:49:48.164 My mother corner frequency of the smallest earthquakes because 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7726-1 00:49:48.164 --> 00:49:52.838 it's it's just too hard to resolve that independently of 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7726-2 00:49:52.838 --> 00:49:55.627 all knowledge of the queue model. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7737-0 00:49:55.937 --> 00:49:59.157 But we can show now for sure that there are these. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7753-0 00:50:00.807 --> 00:50:04.772 I'm hot spatial variations of high frequency energy from 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7753-1 00:50:04.772 --> 00:50:05.607 earthquakes. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7762-0 00:50:06.737 --> 00:50:10.957 Umm, I think the path forward is that. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7775-0 00:50:12.727 --> 00:50:18.967 Ultimately, we should drop the purely in up, up, up. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7778-0 00:50:19.567 --> 00:50:20.397 I'm empirical. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7784-0 00:50:22.767 --> 00:50:24.007 Approach. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7788-0 00:50:24.137 --> 00:50:24.387 So. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7806-0 00:50:24.397 --> 00:50:28.743 So those of us who were doing source studies should actually 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7806-1 00:50:28.743 --> 00:50:30.097 solve for Q models. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7833-0 00:50:31.337 --> 00:50:37.266 In other words, don't just allow the path term to float because 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7833-1 00:50:37.266 --> 00:50:42.917 that ohm ohm that introduces ohm but too many uncertainties. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7839-0 00:50:43.417 --> 00:50:44.707 So I'll stop there. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7841-0 00:50:44.767 --> 00:50:45.197 Thank you. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7858-0 00:51:04.277 --> 00:51:06.737 Alright, thank you for the the great talk. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7867-0 00:51:07.237 --> 00:51:09.367 We can take some questions now. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7892-0 00:51:10.177 --> 00:51:13.745 So if you're, we'll take questions in the room, but if 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7892-1 00:51:13.745 --> 00:51:17.833 you're online, please raise your hand or post your question in 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7892-2 00:51:17.833 --> 00:51:18.417 the chat. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7906-0 00:51:39.947 --> 00:51:40.477 That's proper. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7918-0 00:51:40.487 --> 00:51:45.817 Your high frequency radiation of your larger increased it. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7933-0 00:51:45.827 --> 00:51:49.590 It seems like you haven't just found a variation in stressed 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7933-1 00:51:49.590 --> 00:51:49.837 out. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7950-0 00:51:49.847 --> 00:51:53.878 They're also kind of found a spatial variation in self 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7950-1 00:51:53.878 --> 00:51:55.197 similarity, right? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7954-0 00:51:55.207 --> 00:51:56.427 Because if there was. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7989-0 00:51:58.807 --> 00:52:02.514 If everything had the same self similarity, once you fix the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7989-1 00:52:02.514 --> 00:52:06.282 smallest earthquakes to be the same, everything was similarly 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/7989-2 00:52:06.282 --> 00:52:07.437 be the same, right? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8104-0 00:52:07.867 --> 00:52:11.429 But if you have some region where you do have a self 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8104-1 00:52:11.429 --> 00:52:15.597 similarity and stressed out, and then you have another region 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8104-2 00:52:15.597 --> 00:52:19.966 where where don't, then even the ones you corrected the smallest 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8104-3 00:52:19.966 --> 00:52:24.402 mandates only then we can see in a different city in the stressed 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8104-4 00:52:24.402 --> 00:52:28.502 out the larger nested that I'm not sure that makes sense but 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8104-5 00:52:28.502 --> 00:52:32.804 but it seems like it seems like you found something larger than 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8104-6 00:52:32.804 --> 00:52:37.039 just the differences stressed out that you found and a spatial 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8104-7 00:52:37.039 --> 00:52:40.803 difference in in how much deviation there has been some 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8104-8 00:52:40.803 --> 00:52:42.887 self similarity with magnitude. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8107-0 00:52:43.147 --> 00:52:43.907 Does that seem right? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8111-0 00:52:44.437 --> 00:52:45.827 Ohe should I? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8115-0 00:52:46.357 --> 00:52:47.417 We're gonna try it. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8117-0 00:52:47.427 --> 00:52:47.587 We'll. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8125-0 00:52:47.597 --> 00:52:49.407 We'll see what it's like. OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8127-0 00:52:49.557 --> 00:52:51.707 So yeah, yeah. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8129-0 00:52:54.027 --> 00:52:54.157 The. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8150-0 00:52:56.187 --> 00:53:02.306 From a good point that, but it's complicated by the fact that to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8150-1 00:53:02.306 --> 00:53:03.907 some extent, umm. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8217-0 00:53:13.797 --> 00:53:20.596 I paired all the true spatial variations, in other words, from 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8217-1 00:53:20.596 --> 00:53:27.502 there, when you see the blue is of the larger earthquakes, it's 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8188-0 00:53:20.767 --> 00:53:23.657 Look, it just lets you know that John, John. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8222-0 00:53:23.667 --> 00:53:28.880 Just get over with grandson uh to just visit the animal, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8217-2 00:53:27.502 --> 00:53:29.877 likely that something. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8222-1 00:53:28.880 --> 00:53:30.527 donkeys and stuff. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8230-0 00:53:30.287 --> 00:53:31.117 How smaller? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8258-0 00:53:30.997 --> 00:53:34.761 I checked with them to see how he was doing and I would just 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8261-0 00:53:31.287 --> 00:53:35.607 Which welcome quicks should have blue as well. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8258-1 00:53:34.761 --> 00:53:36.427 kind of thank you for that. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8269-0 00:53:35.697 --> 00:53:37.947 So ohh I. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8278-0 00:53:36.807 --> 00:53:39.027 I'll be giving over the month anyway. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8321-0 00:53:39.737 --> 00:53:44.613 I don't see your point, but in order to be sure of the long, 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8321-1 00:53:44.613 --> 00:53:49.729 long Susan, I'm self similarity aspect of the one would have to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8321-2 00:53:49.729 --> 00:53:52.687 try and food on that effect as well. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8370-0 00:53:53.637 --> 00:53:58.726 Uh, it is a case of generally that the when you make your 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8370-1 00:53:58.726 --> 00:54:03.990 smaller earthquakes, if you assume they have smaller stress 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8370-2 00:54:03.990 --> 00:54:09.606 drops then that does timber lead to non self similarity because 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8370-3 00:54:09.606 --> 00:54:09.957 the. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8379-0 00:54:11.087 --> 00:54:13.707 It's, well, large events are. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8405-0 00:54:15.767 --> 00:54:22.282 Then the constraint so with the ohh the Greenland since yeah 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8405-1 00:54:22.282 --> 00:54:25.487 which is usually stressed out. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8423-0 00:54:26.027 --> 00:54:30.087 We're just compare the little busy. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8448-0 00:54:30.757 --> 00:54:37.200 I one thing that will be influenced by other choice you 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8448-1 00:54:37.200 --> 00:54:39.387 feeling it smaller. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8473-0 00:54:39.397 --> 00:54:44.766 So for you to make that more that will get, I mean we work 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8473-1 00:54:44.766 --> 00:54:48.497 for less than that seems like a smaller. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8485-0 00:54:50.287 --> 00:54:51.867 Well, that's those things always. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8490-0 00:55:02.187 --> 00:55:03.117 OK, great. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8497-0 00:55:03.527 --> 00:55:06.947 Do we have any other questions around? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8502-0 00:55:09.697 --> 00:55:10.417 OK, go ahead. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8512-0 00:55:21.687 --> 00:55:24.227 Based on our size. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8520-0 00:55:26.257 --> 00:55:30.407 That it's just all purity. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8546-0 00:55:31.347 --> 00:55:38.103 Yeah, that those, those earthquakes that her on fault 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8546-1 00:55:38.103 --> 00:55:46.237 falls that have small cumulative displacement or ones that have. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8550-0 00:55:47.047 --> 00:55:48.667 Uh. Uh. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8556-0 00:55:49.157 --> 00:55:51.767 Roughness, high amplitude roughness. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8560-0 00:55:52.697 --> 00:55:53.767 Uh, yeah. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8623-0 00:55:53.777 --> 00:56:00.853 Short wait ones and and that those that are on false that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8623-1 00:56:00.853 --> 00:56:07.319 have large cumulative displacement that they are the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8623-2 00:56:07.319 --> 00:56:13.786 roughest that spectrum is, is much smoother at short 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8623-3 00:56:13.786 --> 00:56:20.618 wavelengths and and so yeah ultimately it it falls that 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8623-4 00:56:20.618 --> 00:56:28.427 falls to the differences in the structure will of the so small. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8626-0 00:56:31.467 --> 00:56:32.157 OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8635-0 00:56:32.987 --> 00:56:37.147 I mean, for example, uh the the giant. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8648-0 00:56:39.197 --> 00:56:41.177 Arizer quake third. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8653-0 00:56:42.097 --> 00:56:42.827 Ohh. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8668-0 00:56:42.917 --> 00:56:49.029 In the Japan trench system, I don't know the moment magnitude 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8668-1 00:56:49.029 --> 00:56:49.917 estimate. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8678-0 00:56:50.707 --> 00:56:55.297 Recently, 8.6 and we know that the source region. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8686-0 00:56:56.437 --> 00:56:59.457 Uh, essentially cross cuts. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8703-0 00:57:00.587 --> 00:57:07.797 Uh sea floor spreading both structure and it broke. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8707-0 00:57:08.887 --> 00:57:09.487 Uh. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8710-0 00:57:10.087 --> 00:57:11.117 Intact rock. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8735-0 00:57:12.207 --> 00:57:17.253 And whereas the interplate thrust earthquakes with the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8735-1 00:57:17.253 --> 00:57:20.557 large, uh, email, Kim displacement. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8739-0 00:57:21.377 --> 00:57:23.507 Uh, black. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8803-0 00:57:24.587 --> 00:57:30.731 Uh, and lack the the I am good, too short freak and short 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8803-1 00:57:30.731 --> 00:57:37.405 wavelength rough roughness and like I think from your work and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8803-2 00:57:37.405 --> 00:57:44.080 others I mean it's clear that these variations and stress drug 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8803-3 00:57:44.080 --> 00:57:49.377 real so searching for under the fault structured. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8806-0 00:57:52.707 --> 00:57:53.857 Explanation. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8813-0 00:57:54.827 --> 00:57:57.847 Maybe useful in? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8815-0 00:57:58.307 --> 00:57:58.797 Yeah. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8829-0 00:57:59.427 --> 00:58:01.897 The yeah, small world events as well. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8832-0 00:58:03.627 --> 00:58:04.717 Yes, goodnight. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8841-0 00:58:06.927 --> 00:58:09.487 Hold up, Peter. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8853-0 00:58:09.497 --> 00:58:13.777 I'd like to suggest top take home message number four. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8870-0 00:58:14.817 --> 00:58:18.869 We need more deep borehole measurements to get below the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8870-1 00:58:18.869 --> 00:58:20.717 earth surface queue layer. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8874-0 00:58:21.817 --> 00:58:22.807 You would you buy that? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8882-0 00:58:23.747 --> 00:58:27.427 Yes, but you you chose not to. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8887-0 00:58:27.737 --> 00:58:28.647 You chose not to. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8893-0 00:58:29.437 --> 00:58:31.167 You chose not to emphasize that. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8897-0 00:58:31.177 --> 00:58:31.537 What? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8900-0 00:58:31.597 --> 00:58:32.217 Is there a reason? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8924-0 00:58:33.267 --> 00:58:38.839 Well, this is, you know, outside of my pay grade, I guess because 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8924-1 00:58:38.839 --> 00:58:42.047 this falls are very expensive, right? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8943-0 00:58:42.607 --> 00:58:46.470 So it's somebody that, you know, write a proposal to, yeah, each 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8943-1 00:58:46.470 --> 00:58:47.897 role one of these sites. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8946-0 00:58:49.597 --> 00:58:49.947 All right. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8951-0 00:58:49.957 --> 00:58:50.257 Thank you. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8955-0 00:58:51.347 --> 00:58:51.947 Umm. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8972-0 00:58:52.427 --> 00:58:55.715 Well, we'll take a few more questions and then then we'll 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/8972-1 00:58:55.715 --> 00:58:57.757 end the formal part of the meeting. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9009-0 00:58:57.967 --> 00:59:02.056 But I I had a question thinking about that you wouldn't expect 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9009-1 00:59:02.056 --> 00:59:05.692 the stress drop to you wouldn't expect the medium to be 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9009-2 00:59:05.692 --> 00:59:09.587 changing, so you wouldn't expect the stress drop to change. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9046-0 00:59:09.657 --> 00:59:13.560 What if you had a setting where the medium did change, such as 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9046-1 00:59:13.560 --> 00:59:16.968 like an induced seismicity setting where maybe you had 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9046-2 00:59:16.968 --> 00:59:20.871 fluid actually, uh, coming in contact with the area that could 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9046-3 00:59:20.871 --> 00:59:21.367 rupture? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9076-0 00:59:21.467 --> 00:59:24.703 Hypothetically, then do you think you'd be able to tell 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9076-1 00:59:24.703 --> 00:59:28.403 between, you know, maybe a fault that has fluids moving through 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9076-2 00:59:28.403 --> 00:59:30.657 it versus one that was dry previously? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9079-0 00:59:32.147 --> 00:59:33.507 No. Yeah. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9084-0 00:59:34.917 --> 00:59:36.317 Ohh, maybe OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9091-0 00:59:36.637 --> 00:59:38.467 Yeah, yeah. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9093-0 00:59:38.477 --> 00:59:39.377 Would be an interesting. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9095-0 00:59:42.097 --> 00:59:42.347 So. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9105-0 00:59:44.557 --> 00:59:47.957 It's like I was curious, like cost. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9180-0 00:59:47.967 --> 00:59:51.849 So yeah, I was just kind of curious, like in Cosmos, if they 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9180-1 00:59:51.849 --> 00:59:55.796 hadn't produced in an area and then started producing and you 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9180-2 00:59:55.796 --> 00:59:59.742 had stress drops from sort of the same location, if you could 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9180-3 00:59:59.742 --> 01:00:03.370 see differences that were actually, you know, that might 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9180-4 01:00:03.370 --> 01:00:07.444 be an interesting you're looking at it and you know and we have 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9180-5 01:00:07.444 --> 01:00:11.390 in the last analysis is that there are a lot of events that's 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9180-6 01:00:11.390 --> 01:00:12.027 I'll come. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9189-0 01:00:12.037 --> 01:00:13.277 So worked up on. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9195-0 01:00:14.117 --> 01:00:15.837 You've got 22. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9198-0 01:00:17.427 --> 01:00:17.787 Thank you. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9203-0 01:00:19.337 --> 01:00:19.637 OK. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9206-0 01:00:21.017 --> 01:00:21.617 Uh, go ahead. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9211-0 01:00:22.257 --> 01:00:23.977 Ohm through the talk theater. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9242-0 01:00:26.527 --> 01:00:30.233 Conclusion too is sort of the the most important take home 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9242-1 01:00:30.233 --> 01:00:34.380 message that you're emphasizing, not is forget about stress drops 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9242-2 01:00:34.380 --> 01:00:35.197 for a moment. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9258-0 01:00:35.567 --> 01:00:38.837 It's a hard result that they're different. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9261-0 01:00:38.847 --> 01:00:40.747 Regional differences in high frequency. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9264-0 01:00:41.597 --> 01:00:41.937 Umm. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9268-0 01:00:44.097 --> 01:00:44.457 Spectral. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9279-0 01:00:44.607 --> 01:00:46.537 Alright, cancel dudes. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9295-0 01:00:47.027 --> 01:00:51.283 And so the question is then, how do we decide whether it's 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9295-1 01:00:51.283 --> 01:00:52.437 sourced or path? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9297-0 01:00:53.377 --> 01:00:53.817 Uh. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9324-0 01:00:54.507 --> 01:00:59.529 And while her said, you know, let's get all the portals to to 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9324-1 01:00:59.529 --> 01:01:00.987 solve the problem. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9348-0 01:01:00.997 --> 01:01:06.469 And you said well, but my gangrene, but it in Japan, there 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9348-1 01:01:06.469 --> 01:01:10.087 are a lot of deep portal seismometers. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9397-0 01:01:10.097 --> 01:01:14.723 And so in the studies that you and your colleagues don't have 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9397-1 01:01:14.723 --> 01:01:19.200 spectral and search props, studies in Japan, presumably you 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9397-2 01:01:19.200 --> 01:01:23.528 couldn't get around that and look only at at the borehole 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9397-3 01:01:23.528 --> 01:01:24.797 slightly perhaps. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9400-0 01:01:24.807 --> 01:01:25.237 Is that right? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9406-0 01:01:26.507 --> 01:01:28.417 Uh, yeah, no, that sounds good. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9427-0 01:01:28.427 --> 01:01:34.868 I I thought, you know, work with the Japan data themselves and 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9427-1 01:01:34.868 --> 01:01:37.527 looking similar issues or? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9448-0 01:01:40.497 --> 01:01:43.750 OK, it looks like there's no questions online, so we'll take 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9448-1 01:01:43.750 --> 01:01:45.457 one last question from the room. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9479-0 01:01:48.027 --> 01:01:51.435 I was sort of waiting for your papers with Yoshi to make an 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9479-1 01:01:51.435 --> 01:01:54.617 appearance at the end, so I'm gonna ask him about that. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9492-0 01:01:54.927 --> 01:01:59.597 You're modeling work has some amazing pictures and it's code. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9544-0 01:01:59.687 --> 01:02:04.105 How things like one of your team politics manages vary around the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9544-1 01:02:04.105 --> 01:02:08.389 focal spirit, almost suggesting of speed of models is kind of a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9544-2 01:02:08.389 --> 01:02:12.539 set of basis functions that you can use instead of large data 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9544-3 01:02:12.539 --> 01:02:13.677 sets to get past. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9563-0 01:02:14.307 --> 01:02:18.487 Just looking at the average spend your old data right? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9570-0 01:02:18.597 --> 01:02:20.807 And is that worth trying? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9592-0 01:02:20.957 --> 01:02:24.613 Is that I because so much structure in the theoretical 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9592-1 01:02:24.613 --> 01:02:27.937 side that doesn't make it into the data analysis. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9596-0 01:02:29.687 --> 01:02:30.587 Yes, I guess. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9640-0 01:02:31.907 --> 01:02:36.825 Ohh what my Jeff is talking about is sort of well, you know 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9640-1 01:02:36.825 --> 01:02:41.743 if we wanted to get from three things I've heard out of our 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9640-2 01:02:41.743 --> 01:02:46.743 upsizing brains, others that was saying that Walmart and get 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9640-3 01:02:46.743 --> 01:02:48.137 stressed dropped. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9649-0 01:02:48.147 --> 01:02:49.807 You wanna get get hot? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9655-0 01:02:49.817 --> 01:02:50.627 Directivity. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9661-0 01:02:51.077 --> 01:02:54.177 You wanted to get some other right? 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9670-0 01:02:54.257 --> 01:02:57.217 So ohh I it. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9678-0 01:02:57.687 --> 01:03:01.157 At least from my experience it it works. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9774-0 01:03:01.267 --> 01:03:06.556 Maybe you know for above magnitude 3 or so, but when you 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9774-1 01:03:06.556 --> 01:03:12.123 try to get down to the smaller ones that were just too much 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9774-2 01:03:12.123 --> 01:03:17.876 scatter and you're looking for, if you wanna see and let as a 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9774-3 01:03:17.876 --> 01:03:23.351 beautifully I'm coherent sort of of signal is a functional 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9774-4 01:03:23.351 --> 01:03:29.197 debatable, but there's just so much scatter in which real data 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9774-5 01:03:29.197 --> 01:03:34.857 and it's hard like yes, in a principle when you have all the 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9774-6 01:03:34.857 --> 01:03:37.827 information, all of these terms. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9779-0 01:03:38.107 --> 01:03:39.397 OK, good. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9788-0 01:03:39.717 --> 01:03:43.277 Try to tease out the man. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9798-0 01:03:44.787 --> 01:03:48.087 I'm gonna genius plan terms as well. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9804-0 01:03:51.407 --> 01:03:51.767 All right. 6f5f39fb-a8ca-4fbe-a848-be815271a1e5/9813-0 01:03:51.777 --> 01:03:53.947 With that, let's thank our speaker from last time.