‘Nick From Home’ Livestream #60 - San Andreas Fault

well good morning everybody welcome to Ellensburg Washington USA the local time is 847 and we will begin our program on the San Andreas Fault at nine o'clock a little more than ten minutes away from now so if you're watching this in replay form go ahead and scroll ahead twelve minutes I guess but we start early with the early arrivals and there's already 200 of you here to visit and I've got some thank yous this morning and even a little story so first things first michael says we're 5x5 Michael you're always so prompt with those comments on each of these videos after they come through on YouTube thank you for that I always enjoy reading those good-morning Japan we've got folks from the San Andreas Fault this morning San Jose that's right Denmark good morning Charleston South Carolina hello Brenda Brenda yeah it's quite breezy here this morning I wanted to be out in the backyard and almost almost did it but 25 miles an hour kind of tired of dealing with the elements we've been doing a fair amount of that the last couple livestreams so here we are in the front porch this morning John good morning garlic fog oh my god we got Oh Santa Cruz all the pressure is on now I actually have to say something meaningful Germany Norway Scotland always fun to see you all Thomas hey how's it going in Germany good it looks like we're functional okay I've got it's been a while since I've broadcast from home here so I've had some things arrive in the mail that I want to share with you well we'll do this quite quickly Nova Scotia BC the Dells hello Jackie Henderson Nevada Mountain View California yeah boy we've got we got Callie in the house okay Thank You Marty and Dale thank you you left something on the doorstep up by the mud room it's a present for bees you and I wanted to keep it intact until I got a chance to thank you and so we'll see if he's if he has fun with this so thank you he's upstairs screwing around I think Bock from Portland Oregon downtown Portland I've met Wesley once in person when I was down there last fall giving a talk so Wesley I thank you for oh my god amazing coffee beans from Portland Wesley thank you so much did you say it was your son maybe that is involved with this roasting facility perhaps regardless we look we look very much forward to enjoying that coffee both Liz and I so thank you and this box arrived look at the postage on this arrived from Thibodaux Louisiana John from Louisiana from Thibodeau thank you for the box of rock samples that we can use in our teaching sounds like you're cleaning house getting rid of some stuff and trying to get some look at how beautifully packaged this is and John from tibideaux sent to all sorts of rock samples to use for teaching samples from Texas samples from Louisiana samples from the Gulf almost $40 worth of postage for crying out loud so if you're here right now John thank you very much sincerely thank you and it's a small world my buddy Scott Brady who teaches at Chico State who pretended to be Angus aged five so that I would answer his question a couple weeks ago he's my age and he's a buddy and he he lived in your neighborhood for a while I forwarded your email too and he was thrilled to see that he his old dad Glenn Brady was it was a football coach back there for many years let's look at the schedule this is the week that was British Columbia geology happened last Tuesday night these are all available of course in replay form we had a guest in the backyard on Wednesday Andrew Sadowski from Washington geological surveys last Thursday night I was up on saddle Rock fighting the elements and had help from Jason and Julie that was like a field trip up at saddle Rock above Wenatchee and then yesterday morning the magical and memorable Randy Lewis if you haven't seen that one yet I think that you'll enjoy it and of course this morning the San Andreas Fault so is there a next week sure there is so we'll do the dramatic reveal the upcoming week I won't see you tomorrow night Monday we take a break from each other Tuesday night 6 p.m. June 9th Spokane geology Spokane geology so I've gotten emails from a number of you asking for that why don't I talk about Spokane and I got a little story for you now we got time so four years not just these live streams but four years any time I talk about Spokane area I have kind of a running joke and I do it very quickly I don't even explain the running joke but I always just say John Stockton south so like oh the west coast of North America wasn't always out at Ocean Shores you know during Pangaea time even the west coast was that at John Stockton house or you know Missoula floods that all that water came over John Stockton salicin you know again you know people if they're not a basketball fan or a sports fan like I am then that just you know but let me tell you why I always say John Stockton South as kind of a reference and almost an inside joke if there's a sports fan on the other end they kind of get a chuckle out of it because they know about John Stockton he went to Gonzaga University is exactly my age he played at Gonzaga this is a basketball player we're talking about John Stockton and had tremendous success with Utah Jazz in the NBA even to this day as the career leader in assists and steals you know this six-foot guy from little Spokane Washington dominated the world of basketball as a point guard and he's right in there with Jordan and Berkeley and Ewing and those guys they're all all the same vintages me and so I followed their careers from a distance of course the whole way and you know Stockton has returned to Spokane and there's a Sports Illustrated article about 30 years ago that I really loved where with all the success he went back and bought a house next door to his parents house where he grew up modest house and he would live there in the summers and with the plan of going back to Spokane and living so he lives in Spokane his two of his kids played at Gonzaga so you watch a Gonzaga game and there's the obligatory shot of John Stockton the audience okay why am I telling you this story can you guess got home yesterday afternoon from my morning with Randy Lewis and Wenatchee it was sent down Thursday third person Thursday so John if this really is you if you really actually did this thank you I'll treasure this forever it's a thrill and Dale if it's you or somebody else who's punking me you can't play with my heart like this I love this guy it's like my mother John Stockton Liz my boys okay in that order so you can't play with me like that so if if this is a prank I need to hear from who did this but if it's not a prank thank you oh we doing okay who else we got here I got two minutes this is out on a walk a long walk so she doesn't need to hear my voice for the next hour and a half Switzerland hey man good to see you again Iowa Germany hey we got a topic that I think everybody knows about everybody's heard of the San Andreas Fault - haven't they around the world so I expect we'll have a maybe a bigger than normal audience this morning Manu in Belgium hello Toronto Cameron England mark hello York Shire Yorkshire India terrific to have you another England distant places always makes my heart go flutter flutter what check my laptop real quick seems like we're functional huh oh I want to finish the schedule sorry I got carried away with my Stockton story well I'm I'm it's like Tiger Beat Magazine you know maybe I should like yeah I should probably hang hang that Stockton thing okay so that's Tuesday night in honor of John Stockton then I won't overdo it I promise on Tuesday Wednesday George Beck very famous geologist here in Washington will tell his story Thursday a very famous geologist named Israel Russell I know nothing about him but he is back in the in the era of George Otis Smith so if you like the George Orda Smith's show not for everybody I realized if you like the George show I think you'll really enjoy this one Saturday morning Kittitas Valley I've got a trick up my sleeve or two that's the valley that I live in Kittitas Valley geology and then I guess we're doing it next Sunday I guess we're doing it I got some book learning to do okay it's already 9 o'clock that Stockton's started took too long give me a minute would you and then we'll get started thank you for joining us this morning well it Pleasant good morning to you well thank you for joining us welcome to Ellensburg Washington we're not in California this morning this isn't a field trip down the Carrizo Plain but we're going down there mentally and we will be in the cozy fort to Fairmount this morning I've got a number of animations and video clips some of which I haven't seen in 40 years I'll explain but we are talking about the San Andreas Fault in California this morning and you like will hold on now you know I've watched a bunch of these and you keep saying that you you just want to stay in Washington like you just want to do the Pacific Northwest like yeah that's kind of your deal and that's true but we're doing a San Andreas Fault show for two main reasons bunch of emails why don't you do a San Andreas Fault show okay fine and secondly there are some benefits for us to go down to California to better help us understand some of the things we've been talking about here in Washington I don't know if you can anticipate what that might be let me give you a little laundry list of things that I think we might talk about this morning I'm Lois of course as always but will I've got a general plan so in addition to just for beginner is making sure we know what the San Andreas Fault is and where it is and how it works we of course will go to a tragic event that happened more than a hundred years ago downtown San Francisco California easily the most famous earthquake in North America's history as far as research as far as research is concerned I'll explain that in a bit we are going to a place that you may not have heard of called the Carrizo plane which I have always taught about we even have a lab that's built around the California section of the San Andreas Fault called the Carrizo Plain and I googled last night I didn't even realize it was it's now a National Monument I didn't I was impressed by that so we'll talk about the significance of the Carrizo Plain and then we're not doing this in order necessarily but I do want to come back to the Pacific Northwest for a discussion of clockwise rotation and Baja BC which you know is a favorite of mine for many local reasons and the San Andreas Fault work the San Andreas Fault history will will shed some light on the validity of that okay that's the plan now just for a moment let's pretend you've all never heard of the San Andreas Fault and you want to know very very basic things or you're a young person learning and doing your home schooling this morning what can we talk about with the San Andreas Fault well I go to the other whiteboard and I share this with you I'm going to tilt it like this so there's not a ton of glare and so I'll kind of hold back here think of a friend okay so let me try to just verbally explain what I have on this board for you first of all this is the state of California Nevada Oregon Washington is not even on this thing okay so my front porch is not even on this map this morning and I have red arrows those are tectonic plates this is the Pacific plate moving a couple inches a year to the northwest this is the North American plate moving a couple inches a year to the southwest this is the Juan de Fuca plate moving a couple inches to the Northeast three tectonic plates and they actually all come together at this point right here it's a place on the Northern California coast called Cape Mendocino in geology we call it the Mendocino triple Junction you can actually stand at a place where three tectonic plates come together and obviously that's a very active place for earthquakes because we have not only the San Andreas Fault coming up from the Gulf of California Baja Mexico bending a little bit north of Los Angeles skirting past downtown San Francisco and then up to Cape Mendocino and then here's the Cape the San Andreas Fault that that takes a hard left-hand turn and goes out to the ocean so the San Andreas Fault does not continue up into the Pacific Northwest that's a very different type of a plate boundary that we've discussed a fair amount called the Cascadia subduction zone so you can think of it as a fault as well but it's a very different kind of a fault these two faults are very different from each other so Cascadia again I'll do this quick because we've spent a lot of time on this Cascadia is where the ocean plate is diving or subducting beneath the Pacific Northwest so there's a trencher and oceanic trench at big drop-off on the ocean floor and we're generating these great earthquakes these magnitude 9 or magnitude eight point five or maybe magnitude 8 earthquake that generate huge tsunami and obviously it's a very serious situation we don't have tsunami with the San Andreas Fault because the fault is running through continental crust and if you haven't heard this before Los Angeles California is not on the North American plate it's on the Pacific plate so LA and San Diego and all these communities on the coast in Southern California SoCal though SoCal folks are riding on a different tectonic plate than they're going a different direction now people lost their minds in 1972 let's say when maps like this started showing up in newspapers and they saw California with a big ol crack in it and urban legend quickly took hold and it still holds today I still talk to people when California falls into the ocean like like they see this map and do their own math and assume that this is an unstable portion of the state of California that's going to kerplunk into the water one day that's ridiculous this is a piece of continental crust that's more than 40 miles thick it's connected to a plate that goes from here all the way to Tokyo the Pacific plate is the biggest plate on the planet you can't just break off a piece and have it fall into the ocean if you understand the depth and the breadth of these tectonic plates and by the way this is the North American plate which is going from the Carrizo Plain where we'll go just a second a little bit west of Bakersfield all the way the North American plate goes all the way to wreck you Vic Iceland so this is not just a regular fault the San Andreas Fault it's not just a regular crack like the Seattle fault or the saddle mountains fault or the fault up by any faults we've talked about here in Washington this is a substantial plate boundary a transform plate boundary so we'll come back to this but let's still setting the tone especially for new people and young viewers each time we have an earthquake on a segment to the San Andreas Fault I want you to think about these blocks these wooden blocks so you're looking down now you're gonna this is looking down from an airplane or a helicopter and I've drawn a fence for you let's pretend this is a pasture a cow pasture or a ranch in central California ok and I'm trying to get this fence lined up so this is a bunch of maybe it's a dry area that it's late in the summer everything's brown ok just like the top of this this wooden block and this is a fence that a rancher put in I don't know 100 years ago let's say okay now this crack of course is the San Andreas Fault and so when we do have an earthquake on the San Andreas Fault if this segment of the San Andreas Fault happens to go the earthquake happens and this is the kind of motion it's a clean break and you're like oh come on it's and this is these are just this is just props it's not really that clean it's not that perfect it actually is it is absolutely amazing and we're gonna see photos and a couple of animations to show how cleanly the ground breaks and Scott crock who may be with us this morning has spectacular drone footage flying right up and over basically right going from south to north and it honest that God looks like exactly like this in real life and this is a right lateral fault meaning that if you approach if you're walking along the fence looking backwards into my image here if you're walking along the fence towards the fault you finally get to the fault and you go over the fence it's gone you have to look to the right to find the continuation of the fault and you're like well okay so right lateral but does it work that way if you walk the other way it does if you start over here and start walking along the fence towards the fault this way you still have to look to the right to find the continuation of the fault okay so right lateral fault this is basically the Pacific plate that's jumping past the North American plate now if I do this in its position please ignore those just ignore those these these red lines okay I just want to show you in a horizontal sense what it looks like so you're down in Mexico I'm up here in Washington in my front porch we're gonna have an earthquake on the San Andreas Fault that's it you see there's no mountain range there's no lifting I'm not doing that I'm not doing this I'm just having almost perfect slippage along this transform plate boundary aka the San Andreas Fault now the San Andreas Fault is hundreds of miles long it's not the entire length of the fault that ruptures at once instead there are segments of the fault that rupture individually and so we get complicated in a hurry so what I'm saying is yes the length of this San Andreas Fault I've already forgotten the number did I write it down yeah I guess depending on how you measure it but a conventional number is the entire length of the San Andreas Fault from the Gulf of California down here in Mexico all the way up to Cape Mendocino is 750 miles long and I'm not saying and nobody is saying in geology that there will be an earthquake the big one that everybody's talking about where the entire 750 miles does the wooden block trick there's no field evidence for that the entire thing is not going to slip at once but in 1906 we did have a very scary earthquake in downtown San Francisco but it wasn't just downtown San Francisco 350 miles so not 750 I'm sorry 300 miles 300 miles the the northernmost 300 miles of the San Andreas Fault from Cape Mendocino down to I think in San Juan Bautista that entire segment ruptured and the Pacific plate side of the fault in 1906 in many places including point raised just north of San Francisco moved 20 feet you want to see it 20 feet now I'm talking about 1906 the northern segment of the San Andreas Fault okay we're minding it on business I actually have some old newly discovered footage from downtown San Francisco a couple of days before the great earthquake and then I also have this exciting footage from two weeks later exciting's the wrong word it's tragic but I'm talking about that earthquake 1906 now what did I just say I said that the 300 miles segment of the San Andreas Fault that's in the northern portion not the entire length but when the earthquake happened in 1906 here we go pumped into the rocks strain building for centuries and then finally 20 feet of movement in other words a fence our fence here is broken cleanly and the Pacific plate side of it shifted 20 feet so I'm not saying the fault ruptures 20 feet every time there's an earthquake there's variability there but that 20 feet I think it's actually technically almost 21 feet measured in point raised is the biggest offset that has been measured so far on the San Andreas Fault now speaking to that let me show you a lab that I wrote with a guy that I used to teach with called Charlie Rubin Charlie got his PhD at Caltech the California Institute of Technology which is kind of one of the main places to generate earthquake scientists and Charlie was fresh out of that program and came up here to Ellensburg and we taught a field class so we were always I told you about that Owens Valley field class that we used to teach for 20 years and we'll be teaching students how to map along faults this is the Owens Valley fault it's kind of a this is more of a normal fault that's a offset cinder cone I'm just showing you an example of another fault in that we know that there's lots of faults in the state of California but the point is these fresh faults meaning these faults that have not been concealed by lavas or eroded back many of these faults have earthquakes that are recent enough were those those scars on the landscape are still as fresh as as it looks like it just happened yesterday and it kind of did geologically so I can't remember why we did this but at some point maybe 20 years ago I said Charlie you've been doing all this research on the San Andreas Fault right yes I have this is me and Charlie talking now in 1998 or something and I said well you use those Trent you actually trench across the San Andreas Fault yes we do we rent a backhoe we have somebody we hire somebody truly a backhoe digging perpendicular perpendicular to the trend of the fall so here's one photograph at the Carrizo Plain where we have a trend of the San Andreas Fault again you can see that there's a linear trace and so Charlie and his bread he worked with Kerry sieh and some others Tom Rockwell and there's still people doing this and they're taking back hoes and digging a trench just like if they're putting in a new cable in your front yard you know the workers come and they they do the big scoop and they dig in well there's backhoe trenching across the fault and then there's excavation or in other words cleaning off the walls of that back hole trench and then you look for layers that you can absolute age date and try to figure out how many earthquakes there have been on that particular segment to the San Andreas Fault and it's a it's an approach that's been used for 30 40 years by now so anyway I just want to give you a little glimpse because we have a little bit of video from this area so in this geology 101 lab book if we get snowed out of a particular field trip we can't go out because the weather's too bad then I say we can't go out to thought today sorry we're gonna do the Senate dress ball lab instead it's like a rainy day or snow day laughs and what we do is we give the students this is at Central now my school we give them a topographic map of the Carrizo Plain a particular segment again I'm I'm designing this lab based on what Charlie is describing to me about what what he kind of does so this is old school now this is you know more than 20 years ago and we've gotten topo maps with contour lines and power lines and jeep roads but you can obviously see there's the San Andreas Fault a major plate boundary coming right through in fact there are streams that are flowing out of the hills and then the streams suddenly do this big crazy zigzag and when we go in the cozy fort you'll see better images of it well we don't have a cosy for it especially 20 years ago we didn't have the internet 30 years ago so we would give our students these these aerial photographs and they would you know line them up and then they would start looking at these drainages let me let me turn them around for you come on baby come on baby you can do this you can do this what oh yeah okay I'm overlapping the photos properly here so you can see these are kind of overlapping sets but the point is we have certain stream channels that are flowing directly across the fault there's just a little bit of a zigzag to them as they cross remember that each time there's an earthquake the Pacific plate suddenly lurches forth but it turns out that these two streams here used to be connected to these two guys over here so can I do this kind of it used to be like this and now it's like this so these are actually beheaded stream channels they're dry they don't have any water in them anymore because there's been a number of earthquakes to offset that stream system so instead of using fences you can actually use natural linear features to measure the offset I'm spending time with you down at that level I'm kind of setting you up for the cozy fort basically so the students in an hour and a half or something work through the photos they actually truly slap their ruler down on the trace of the San Andreas Fault and they measure between channels that they know used to be together but now have been offset so they measure in millimeters on the map and then they use the scale of the map to convert the millimeters to ground distance and then we give them the age of the actual channel let me see if I can find that so they can figure out right so we say here I'll just read it to you this is from Charlie now your your to offset answers in meters on the previous page are the largest measurements of offset here at the Carrizo Plain but not all offset measurements are in this ballpark the smallest offset on an active Channel here in the Caruso plan is 8 meters in other words 8 meters 2024 feet for 1 earthquake which means that for every earthquake that are occurred here in the San Andreas Fault the ground moves a minimum of 8 meters so then we ask them how many earthquakes if we know the average offset how many earthquakes are recorded if we have offset that stream channel by X amount and then we give them the age of the channel that's a whole different process to figure out how long that channels actually been there like the stream hasn't always been there but if we can give them the age of the channel and in the case of the Carrizo play in the channel that we have the students work with is that channels been there for 3,700 years well then they have a number of earthquakes age of the channel simple math you figure out the recurrence interval the average number of years between events and then the last thing I have them do is to actually figure out how old they will be the next time a big earthquake will happen in that particular area so my point is to show you that detail and to give you a sense that these are not guesses this is based on data of course trenching ages of stream channels using some basic math on a particular segment and doing something to forecast but if your waiting for a message that we know how to forecast earthquakes I think you all know we don't see we don't still know how to do that and it's it's a game of choosing your words carefully when you talk about the future because the stakes are quite large we can comment more on that if you like I'm going to continue to roll I see comments coming in if you're if you're new to us we're going to do some live Q&A but I can't read your comments right now we got more than a thousand here ok we'll keep rolling so I want to share some exciting again wrong word for this topic sorry captivating footage from 1906 that's what I wanted to kind of talk about with the Carrizo Plain but we'll come back to it before we go into the cozy Ford I have two other things I want to comment on I'm not flipping you off many know here in the Pacific Northwest we have a rather dramatic rotation in a clockwise sense with crust throughout the Pacific Northwest Washington Oregon Northern California let's go back to that other whiteboard and I'm guessing you already noticed that I had that on here so these green arrows are not flipping you off so we're doing individual segments of the San Andreas Fault producing offset on occasion it's frustrating though because some segments haven't done much in the last 200 years other segments have gone semi-regularly some segments appear to creep in other words they they gradually slide and don't have this build up of stress and ultimately strain in the rocks so there's lots of variability a long strike along the trend of this San Andreas Fault but regardless the cumulative effect of eventually moving the Pacific plate north if you just think of it as 20 feet being released at a time again we're going talking about centuries between events the cumulative effect is taking a portion of North America the leading edge of North America in essentially being this portion of North America is being influenced by this Northwest bird movement of the Pacific plate likewise the western portion of Washington and Oregon being influenced by the motion of the Juan de Fuca plate and as a result because these two plates are doing their thing regularly this is this does not stop and start this is gradual this is ongoing 30 millimeters a year every year 30 millimeters a year but we should be having 30 millimetres of year along the San Andreas Fault but it's stuck in most places and you build up 30 millimetres of year of strain until you finally have a release and we do our 20 feet or 15 feet during an earthquake on the San Andreas Fault but I'm getting sidetracked then there is a tie between our clockwise rotation up here and this motion on the San Andreas Fault although when I was thinking about this this morning I had a new thought I don't know how many years I've talked about the clockwise rotation and it's possible I just woke up too early this morning and I'm not thinking clearly but I think Rhea Wells who is kind of the Godfather of documenting this clockwise rotation before we had GPS in other words he has field geology evidence for this clockwise rotation around Pendleton Oregon I think he's got clockwise rotation going back 50 million years 50 million years of clockwise rotation but we don't have 50 million years of San Andreas Fault activity so I think that might be a new thought for my brain why do we have 50 million years of clockwise rotation if we don't have 50 million years of San Andreas Fault and are we sure we don't have 50 million years of San Andreas Fault yes freelancing freelancer we've done this before in past sessions but this is my favorite diagram from my geology 101 class that shows that the Senate for his fault is born roughly 20 million years ago we'll see some animations from tan yacht water and redone by Gen 2 Johnson to show this we don't have a San Andreas Fault forty million years ago and yet wells is telling us that we have some clockwise rotation as early as 50 I need to look that up number one make sure that's true but I think that's right so that's that's that's us that's all my to-do list why is that but as we do more and more of North America crossing these specific rides we have more morrible lengths of the San Andreas Fault until eventually we will have nothing but the San Andreas Fault along the west coast of North America our future here in Washington ten million years from now will be a welcoming celebration of the San Andreas Fault coming up through us no more volcanoes the subduction will be gone last comment before we go to the cozy fort you know that I love this and it's not just me a growing movement among research geologists are realizing that Baja BC that a large portion of Baja Mexico is now up in British Columbia and a little bit of it is in northern Washington but that is possible if we look at these motions and this history and this 20 feet per quake story but if we have what is that 25 million years worth of time we're going to be able to move almost 2,000 miles along the San Andreas Fault like structures where'd it go there it is when I talked about the Straight Creek fault which is a little bit younger than Baja BC I'm scattered now but I hope you can stick with us a neighbor of ours K who lost her husband Chuck a couple years ago and tuck was a loyal attendee of all of our they both were but tuck in particular had a lot of interest in geology and and she was going through tuck stuff and she just happened to drop this off at the house which actually was now that I think of it it's part of the reason we're doing this session this morning because she gave me this that used to belong to talk who talked we used to study down in California and this is an important quadrangle of an important geologic map done by Thomas Dibley who had spent a whole career studying a bedrock in the state of California 60 years of field mapping that's not an exaggeration 60 frickin years and I think that's the first little thing I want to read to you on the cosy fourth but before we go in there this is an important quad because he's in Palo Alto some of you that name that's where Stanford University is located and the San Andreas Fault runs very close to Stanford University we're in the San Francisco Bay Area well another segment not the Carrizo Plain now a different segment of the San Andreas fall so this is field work done in 1963 let's pause 1963 this is not a plate tectonic scene yet we're years even really a decade before plate tectonics is fully embraced by the world and yet Dibley is saying here's my map I've covered every square inch of the ground in the Palo Alto quadrangle here's their Stanford University thanks for the thanks for this gift Kay Mountain View Sunnyside Los Gatos San Jose okay Los Altos and he's just making a map he's not he's not trying to you know say anything about plate tectonics or anything he's just said look this is the map man and we've got rocks on this side of this fault and he didn't discover the San Andreas Fault you know since 1906 at least we knew about the San Andreas Fault existing but he's saying this stuff that's on this side of the up look he saw right here the bedrock on both sides of the San Andreas Fault and here Stanford University is so different he actually did two different diagrams he said I cut this step on one side I'm not flipping you off we got these rocks on the west side of the San Andreas Fault we got these rocks on the east side of the Senators fault they have nothing to do with each other and he was the first geologists as early as the 1953 season I think 1953 is the first time Dibley said I don't know how it's possible but I think this stuff got moved like 200 miles away from it where it used to be there was no idea in 1953 how to explain that but the understanding of plate tectonics basic plate tectonic motion and tectonic plates and moving things hundreds of miles if given enough time all came from geologic maps like this and Dibley was right in the middle of laying the groundwork for our understanding of not only how the San Andreas Fault works but in a broader sense how plate tectonics works so in many ways the San Andreas Fault is one of the key places maybe the key place hmm one of the key places to help us understand and crack the code on how the earth works with this plate tectonics business a huge revolution in science as you all well know all right not bad 934 I think I've got easily 15 minutes in the cosy fort with you hope you're up for it no big deal well we may have a record number watching at the moment which probably means we have people who are thoroughly confused I don't understand what's happening now well my dad was a good dad and we would make forts in the basement because he was a pack rat he had carton but he couldn't throw out a cardboard box to save his life we made elaborate my sisters and I elaborate forts out of cardboard boxes in the basement and he'd come down and hang out in our cozy forts with us and that was his name cozy Forbes we'd have lunch in there we'd have three books in there together so this is my homemade little cozy for it in honor of my dad I'm taking extra time because this is this is good stuff here I think we're doing ok and this is the part where people walk by the house Glen mommy there's that man again what is he doing oh he's a little strange dear we don't really ask questions he's a large man that appears to have lost his mind let's pray for him Sunday morning oh ok we're getting rid of my voice mercifully we're cranking the volume good bye live stream for the moment Thomas Dibley or Dibley I'm just on Wikipedia here I just want to tell you a little bit more about him born in 1911 Santa Barbara died in Santa Barbara 2004 an American geologist best known for his geological mapping he is also known together with co-author Mason Hill for the a certain in 1953 that hundreds of miles of lateral movement had taken place along the San Andreas Fault in California an idea that was radical at the time but which has been vindicated by later work and the modern theory of plate tectonics Dibley was one of the most prolific field geologists in American history and over a 60-year career and field mapping including 25 years with the usgs left a legacy of 40 thousand square miles of geologic maps covering approximately 1/4 of the state of california continuing a theme we've had before where many of us love geology so much that we continue it after retiring Dibley retired from the usgs in 1977 let's see he was 66 years old and the following year began to mapping the geology of the Los Padres National Forest as a volunteer although retired he mapped the geology of more than 3000 square miles in the National in his late 60s and early 70s what can you say amazing stuff Oh God where do I start you know what we're gonna start with old Scott Scott are you watching Scott Krunk it's got lives in Washington I don't know and he flies a drone occasion I don't know why you were down there Scott but you captured what I think is the best video of the San Andreas Fault and I use it all the time and I am grateful for your allowing me to show this so Scott has a drone this is five years ago Scott's here good thank you Scott actually Scott why were you down there and did you did you pick a certain time of did you think out the time of day to get that shadow just right could you give us a little background on how you captured this because that shadow is perfect we've got a delay here Scott oh you were on vacation did you luck out with that shade or did you figure out that was the best time of afternoon to grab it the Pacific plates on the left yes so you thought it out I mean you needed perfect light perfect time of night or afternoon I mean this supposedly is what the senator said this the straight Creek Fault in Central Washington used to look like when it was still active but it's been dead for thirty-five million years and so of course you bury it you you rode those scars but my god and now that I'm looking at this with you well what's happened is at the end of it I guess it is there's probably more Scott don't be mad at me I think I just clipped it off there please don't be mad it's gone Scott can't we be friends Scott Scott can't we be friends okay I'm scattered you know I'm scattered 1984 I'm in geology 101 and I remember watching this movie now 1984 I'm in weeks Hall the auditorium in University of Wisconsin Louie Maher is our instructor professor and you got to load the film into the film projector or maybe a grad student is doing that in the projection room in the back old timers you know what I mean you're taking the film you're getting it into the projector you know it's like an old movie house but that was what we were using in the classrooms me as a student now and in addition to see remember just the nostalgia coming back to watching this this is called San Francisco the city that waits to die made by a British outfit I believe you'll hear the narrator but one of my memories is the professor Maher said he always gets choked up when he shows this because he sees the boys and the dog with the footage from Alaska it was like wow of this professor is an actual human being I never really imagined him having a life like I only thought he existed up there with the podium and everything so that left us a big impression on me that this guy was willing to admit that he got emotional watching this kind of a weird memory but anyway I want to show a couple pieces of this to you this is 1972 I'm guessing there's excitement about discovering the San Andreas Fault discovering plate tectonics and we'll show you one clip right now [Music] scientists believe that many of these lives could be saved the key to saving them is understanding the causes of earthquakes to do this they've returned to the 1906 earthquake the most closely analyzed earthquake in the world it shook over 50,000 square miles of California and afterwards scientists observed in country lanes and farmers fields an extraordinary series of breaks in the ground photo by jakey jakey Gilbert JK Gilbert any more coffee [Music] okay we're gonna do more of that don't be don't be mad at me the rupture stretched for over 200 miles I know I jumped the gun we're gonna do it 1906 San Francisco [Music] the rupture stretched for over 200 miles the longest surface break ever recorded it followed the line of an ugly and unusual land formation that runs throughout California ugly the San Andreas Fault not as good as you Scott it looks as if someone had dragged a knife across the land leaving a jagged linear scar geologists suggested that this marked a break in the Earth's crust which plunged onwards for 20 to 30 miles [Music] he never drawn the land surface they argued had ripped open because one side of the fault was trying to move northwards in respect to the other side pressures and the rocks had slowly built up until there was suddenly released like an uncoiled spring the action of the rocks lurching past each other created the earthquake this ferry is now accepted in 1906 the sudden movement tore apart farmers fences by as much as 20 feet of the California Institute of Technology professor Clarence Allen we've been able to identify rock units that have been split by the fault and we can now find the two halves of these rock units and see how far they are separated along the fault for example these two rocks I have in my hand our rocks taken from two different sides of the fault 160 miles apart but they are a very distinctive rock type so similar in fact that we conclude that they must have a one time been together part of a single rock unit that was split by the fault and separated so that they now a lie 160 miles apart along a branch of the San Andreas Fault in the southern part of the state now is that movement going on today can you can you feel the excitement I mean they're making films first of all that's kind of new there isn't a lot of this kind of field base stuff and they got the groovy music and all that at the early 70s but it must have been an intoxicating time to be a geologist right there with these major revelations coming in almost weekly and to give you a better sense of that this cocky guy I always romantic I think at least I remember us kind of laughing when he said it because we were watching this in 1984 of the film it was made you know 12 years earlier check out this old computer and what this guy says from measuring points like mount diabla data on earthquakes on fault movements are sent back often simultaneously to the earthquake Research Center near San Francisco the problem is analyzing the data a first step is to display it dr. Darrell wood Darrell would possible to locate earthquakes just a few seconds after they arrive we're trying to do is couple a display of this type to the very rapid detection of these earthquakes and thereby almost instantaneously display the information what I would like to show for you to you now would be all of the earthquakes that have occurred in the year 1969 plus two years two months in 1970 the earthquakes will be seen on this planned view of California the longest diagonal straight line on the left is the San Andreas Fault it runs down from San Francisco Bay the two smaller diagonal lines on the right are branches of the fault the time will be condensed by a factor of 1 million to 31 seconds we gotta stick with this up here on the screen will be proportional to the size of the earthquake if it is a large earthquake it will be a large X but a small earthquake will be a dot the important thing to watch for are the patterns in the activity and where the earthquakes are occurring relative to these faults I'd like to remind you that San Francisco is in the upper left-hand corner of the map and you should also notice as soon as we start the run that the San Andreas Fault in the San Francisco region is not acting almost as if the fault is locked and refusing to yield hits strain energy with the earthquakes this lack of activity near San Francisco could very well be a very dangerous thing all right here we go so he thinks he's on to something about predicting I witnessed this fact that only a few very lonely earthquakes are occurring along the San Andreas Fault the principal activity is all along the southern area of the major false Buffalo boy this is longer that I wanted but we got it get this proclamation from this guy the next step is to display not earthquakes but the small geophysical changes that precede large earthquakes to display these as they happen before the earthquakes occur yes Colin correct recently a swarm of small earthquakes hit the town of Danville which lies at the foot of Mount Diablo to the residents of Danville if they'd been in bed at the time these earthquakes would have felt as if a 20 stone man was shaking the bed the key to predicting such earthquakes is detecting the warning signs which precede them 1972 days 13 hours before the Danville earthquakes there was a series of geophysical events that appeared to give warning of the earthquakes themselves hidden away in the mountains and valleys along the San Andreas Fault instruments detected these changes tomorrow in particular some showed that rock strata near San Francisco heave got tilted 13 hours before the earthquakes here at the Stanford Linear Accelerator one of the world's largest computers processed the data before the earthquake took place and displayed it from the top of the screen a line will appear and point to the earthquake as the rocks actually tilt here it comes now the anomalous activity begins the arrow is shortening indicating tilt up away from the fall it is now starting to rotate in the direction of the epicenter and it's pointing to the earthquake the tilt activity around the fault forces the tilt to go in Northridge that's the end of the sequence what we need to do is have a system of this type that will allow us to cross correlate this information in simultaneously while earthquakes are occurring all the Americans optimally go to these first hopeful signs wait it's not a curve in the next five years my opinion that we will be able to predict him here in the Japanese village of Matt sushiro scientists well it's 40 years later fifty years later we still can't do it and I know some of your commenting in a Dutch inist can do it let's not go there I'm sorry that was way longer than I wanted that I wanted to get his quote and move on but maybe you saw something I got to show you this one this program is running long by the way just in case you haven't figured that out it's Sunday I find this fascinating this is we're gonna look at this it's three minutes and 26 seconds in 1906 a massive earthquake and out-of-control fire devastated San Francisco in 2017 a century-old film turned up at a California flea market after seeing the discovery on Facebook photo historian Jason Wright bought the film on a hunch that it might be long-lost footage of a crippled San Francisco shot two weeks after the quake we recently spoke to right from his home in hi Burton England about the secrets revealed in the now restored film April 1906 a major earthquake struck San Francisco the quake was very large in itself but most of the the damage was actually caused by fire which ripped through the city pulse waves of San Francisco were completely leveled into droid we've known about this film for over a hundred years but it's more of a rediscovery it's it's been lost all this time what it actually is is about one to two weeks look at that the earthquake actually hit it's basically a trip down Market Street done by the Myles brothers and there's a famous tape that most people have already seen which went down Market Street just a couple days before the earthquake hit the previous footage of the trip down Market Street only survives because one of the Myles brothers actually sent that footage over to their New York studio literally one day before the earthquake hit this is a missing film of their trip back down Market Street once the earthquake had already happened so it allows us to really compare and contrast they made for an after and see the devastation that actually had gone on all the hustle and bustle that he saw on the the previous trip down Market Street that's all kind of gone and people are crying kind of down and kind of shuffling around you know all the pomp and all the rich people going passing their their expensive cars that's completely gone new as you move down Market Street you see most of the buildings are gone at this point and you see a lot of ancient steam engines they used to put chains around the buildings and hold the buildings down using the steam engine as you get down to the words the bottom of Market Street though you get to the Ferry Building and this is the most important part of the film for me you see the the human cost of the actual tragedy you see a lot of people basically in line you know from rich to poor everybody and they're waiting for ferries and boats to take them out of the disaster area and then towards the end of the movie it flicks through a few more scenes you see dynamiting taking place you know City Hall being blown up for example which is but disconcerting and then the demolition of cragars department store I wanted to bring this to people of San Francisco I wanted to make sure we conserved it for future generations because I think is very important with this film you see the human element days of amazing happened I thought that was really cool hope you did too we're gonna continue I'm getting hot in here man but we're gonna do a few more I saw Oscars name Oscar thank you for sending me the link I didn't know about this till I opened it up this morning so thank you for the email I don't know anything about this guy this is a I'll show you what the channel looks like first of all that's life so are you aware of this if you look in the lower left you'll see the YouTube channel CA seismograph and it's a 24 hour 7 days a week stream showing seismic data I don't anything more than that and I I know that many are consumed by monitoring earthquakes for a whole bunch of reasons and there are many channels I assume like this but again there's the YouTube channel the lower-left and just wanted to share that with you I don't know anything more Oh Oscar you can chime in if you know more if you're affiliated somehow with that with that group I'm all over the place now but you already knew that here's a map of point raised a geologic map of point raised National Monument or National Seashore something like that we're north of San Francisco now Liz and I were down there for a wedding a couple summers ago actually Scott Brady's kids wedding in San Jose and we spent a really wonderful day up in point raised and you see the pink there in the red well first of all you notice the San Andreas Fault coming right through so look at the look at the shape of this thing that's the trend of the San Andreas Fault coming right through which means that this is the Pacific plate side which means this is granite that should be down at the southern tip of the Sierra Nevada mountains has been moved more than 300 miles one earthquake at a time 20 feet at a time but if you have 20 million years you can do quite a bit of offset so if you only go one place well I don't know about California details so I'll keep my mouth shut but this is a famous place among geologists point raise our ayes the hits keep on a common what's this oh this is another little old film from the early 70s that actually visits the Carrizo Plain I didn't know this existed I would have used this in my lab if I had known it existed but I found it bees you woke me up at 4:30 this morning so I was finding all this stuff at about 5:00 this take place very slowly they are some forces that come into play a rarely experienced directly by man but ruthless motion along the fault is here in the geologic record of the land here we go one of the most dramatic examples of this proof can be found in the coronal plane where the dry gullies of training Creek depend to the fire those are the gullies that we've been teaching about we'll be music mainstream do not flow in a straight line at the ball they veered sharply to the north the offset of history the result of motion along the Bob Bob tripping right now this model shows how the offset was produced do it land on the western side of the fault has been moving slowly northward with relation to the eastern side yes where the stream crossed the fall trace this horizontal motion diverted the flow that's really well done further motion completely interrupted the streams fat of course they're showing creep it's not that gradual but you get the idea eventually the waters of the stream here oted a new path into the land but again the new stream with the object that's well done they did a great job with that today the stream is displaced about 20 meters to the right where it crosses the fault line it's not it's probably the result of several hundred years of fault motion several hundred years of thought motion they were a little bit off on that one otherwise terrific stuff okay it's ten o'clock we're gonna come to your live Q&A I feel like I got one more thing to show you what is it now I'm hunting around oh of course is that it yeah the last thing I want to show you we pulled back to geologic time again we pull back to the last 20 million y I feel like Randy Lewis now we pull back and we pull back and we have Genda Johnson remember her animator in Portland taking an older animation by Tanya Atwater remember her Santa Barbara and folding it in to work with Bob Butler I'll let this speak for itself but it involves gulf of california opening of the gulf of california showing how complicated the motion can be along the San Andreas Fault instead of the rather simplistic view that you've heard from me so far this is three minutes and I promise we're out of the cozy for it I can barely breathe as it is so we're I need to get some fresh air but I can hold on for three more minutes Genda Johnson do it California stepping back we see that these earthquakes to find the southwestern margin at the North American plate between California and middle America here we'll focus on the Gulf of California rift son but divergent margin which is propagating into California it is a transitional corridor that connects the East Pacific Rise spreading Ridge to the south with the San Andreas Fault zone in California extension and strike-slip faulting are causing Baja California to separate away from mainland Mexico thereby opening the Gulf California as though it would be in reality the waters of the Gulf of California hide connecting stair-stepping seafloor spreading ridges with right-lateral strike-slip motion on classic transform faults this collection of faults and ridges forms a continental rift system that is tearing the Pacific plate apart from the North American plate if we zoom in we can see the processes occurring as the lithospheric plates move apart heat rises beneath the mid-ocean ridge magma forms at shallow pressures and creates new rock at the spreading ridges the plates move away and conveyor belt like fashion movement between the ridges is accommodated by transformed faults where large earthquakes occur due to friction between the plates smaller earthquakes also occur along the ridges backing out to map view we see the simplified San Andreas blood cutting through California as the movement of the plates continues along this plate boundary it is forcing Baja California away from Mexico and causing Santa Barbara and San Diego to migrate northward and we're in San Francisco the Giants and the Dodgers with the crosstown rivals once again more detailed book we will go back 20 million years to watch how the Gulf and coastal areas developed good do it nice this animation by Tanya Atwater shows a tectonic model for the 20 million year evolution of the region depicting the rotation of the transverse range blocks the breakup of the continental shelf as well as the opening of the Gulf of California as the Pacific plate brightest northward against the North American plate the Baja California peninsula and most of southwestern California is a remnant of the North American continent it was sheared off and moved to its present position earthquakes in the Gulf or more of a nuisance than the threat however the on land part of the spreading Ridge extends into Baja California Mexico and the Imperial Valley of California okay this transition whoo Thank You Genda that was a long cozy fort longer than I wanted but most of you are still with us thank you does that really say 1,200 people I mean yeah 1,200 nice you love your son earthquakes it's time for live Q&A you know that I'm a Washington guy but I will do my best to address things and we have plenty of California viewers this morning so they may be able to answer some of your stuff directly or correct me I'm fine with that so let me find the live stream again I'm glad I'm glad I'm glad I'm in here it is it's cooking out there hopefully liz has some rocks in her pockets popping out the chat like a boss going to Liv's chat instead of top chat cuz that's how I roll I'm muted mercifully he Scrolls back in real time looking for uppercase looking for auto-lock uppercase Evelyn age 7 how can only part of a huge fault move or slip to cause an earthquake it's possible Evelyn because the crust is kind of elastic it can store energy so if you think if I was really strong Evelyn this was one of our wooden blocks right Evelyn if I was really super strong like like incredibly like impossibly strong for a person I could take this wooden block and I can so squeeze it so hard Evelyn that it would actually start to squish a little bit like a like a marshmallow can you imagine my wooden block acting like a like a marshmallow like it actually can change its shape just a little bit and so that's kind of the view of the bedrock along the San Andreas Fault if you if you have let's say a hundred miles of the San Andreas Fault slip it doesn't mean that the entire length of the fault ruptures and a bunch of that energy then gets transferred to crushed nearby I think physically that's the wrong way to explain it but I'm spitballing as we go Evelyn I guess another way to answer your question is it's maybe difficult to explain how it's possible but it's important to say we have all sorts of very careful field evidence to say that it has happened that way that there's these individual segments that have ruptured we've seen that in historic times and we threw that trenching we've seen prehistoric evidence as well aged seven Evelyn you're a superstar Rhian or regime how many millions how many million years it will take Los Angeles to move to Alaska well interesting question so the punchline again we're back to sports fans you know back in New York the Giants and the Dodgers were crosstown rivals and now the the Dodgers play here and the Giants play here but in twenty more million years we're going to have this motion of this portion of the crust and so we are going to slide Los Angeles up to San Francisco and the Dodgers and the Giants would be crosstown rivals again hahahahaha but as you heard me briefly say that the days of the Juan de Fuca plate subducting minute the Pacific Northwest will not go on forever because North America as a whole continues to drift west and will eventually cross the Juan de Fuca Ridge which is generating the one-two Fuca plate and so we will thirty million years if we could all come back thirty million years from now wouldn't that be fun number one and number two we could come and see that there's one big master san andreas fault connecting the Santa dress as we know it with the dude out excuse me excuse me so to answer your question 100 million years Los Angeles to Alaska wild guess but 20 million years just to get LA to San Francisco thank you for your question Robert why doesn't lava come up from the fall between the Pacific plate and the North American plate thanks for your question lava does come up in Nevada where we have normal faults while we have crust being relaxed crust being thinned crust being broken and we get a Rift Valley in the process but with the San Andreas because we're really not extending the crust we're just doing this lateral motion remember we're doing this there's just notice the crust is still thick and the crust is not being relaxed or extended or thinned and so it's just not possible for that magnet to come to the surface so yes it's a rare plate boundary Robert to have earthquakes but no volcanoes we have earthquakes in all types of plate boundaries we have volcanoes up most types of plate boundaries but not transform like the San Andreas and not two continents colliding either thanks for all these questions Susie could Long Valley actually be the result of a hot spot that was formed two million years ago a theory of hotspot formed forming new caldera to the east in Nevada the Long Valley caldera is puzzling to me and I think to most maybe to all there is in Eastern California an incredible call there the Long Valley called there a supervolcano that exploded what is it seven hundred and sixty thousand years ago I think and I know of no hot spot trail or any indication of a major heat source like the Yellowstone story so if there is a track where a hot spot used to be offshore and now it's beneath Eastern California I'm unaware of that I don't think anybody's aware of it so I don't know what to do with that I would do probably a program on the Long Valley and the bishop tuff and all the wonderful stuff mono craters are all that stuff but I don't think we know that much about that area may be it may be a california geologist does know Tonya Atwater and Brian Atwater are not related isn't that weird two of our most important North American geologists in the last 50 years no relation Kathy and Brisbane can you explain the kind of Santa Barbara rotation I really can't that's tan yes I was I was want to call her Tonya that's tan use animation based on detailed mapping in the Santa Barbara area that's where she lives and has worked for most of her career so there's no questioning that rotation happened but I don't I don't know why that rotation happened there like I really have no insight for you I'm sorry Adam how far into the Pacific plate does the Mendocino Ridge go that is something I've meant to do oh I was going to read this to you let me answer your question first and then I'll read this to you oh I was going to go here maybe if you just go to Google Maps and you look carefully at Cape Mendocino look at these fractures look at those fractures now this is Cape Mendocino again I'm looking backwards into the phone yeah yeah that's that's it so I don't really know if that's technically the San Andreas Fault or if that's the Mendocino fracture zone that's different or it's one in the same but I don't understand the significance of those guys as well as I've never really understood the details of the submarine canyons they're so huge and the explanations that are out there just they don't work for me so another reason to be interested is I think it's a thing I'm spitballing you know I think it's a thing that tsunami that crossed the ocean are influenced by something like this and it's not an accident that Crescent City California gets hammered by tsunami because of that fracture zone on the floor I I mean I'm totally confused by all of that I think there's something going on there I've always meant to look into it that's my best answer which wasn't an answer at all really Adam but it is an area that I I'm intrigued by and I've kind of reminded that I might I don't know maybe I'll do a live stream on that Tim it seems that Southern California could eventually separate from the mainland just like Baja California well I agree Tim but not on a Tuesday morning not on third person Thursday and there are certainly people that are firmly of the belief that Southern California is just going to plop into the ocean but i 100% agree with you that if under asphalt martian we talked about tens of millions of years that is for sure we're going to create a new exotic terrain and it's going to be headed towards Alaska or Japan it's a it's a if you've been with us for exotic terrains and if I haven't said this before we're witnessing the birth of his in exotic terrain this is how you can get continental crust riding on an ocean plate this we're starting to lose a valuable piece of our real estate Furley the first time we've been receiving pieces of land exotic terrains for the last 200 million years it's about time we give back and we are with Baja I don't know if we didn't ask them permission or they didn't ask us permission or whatever uh so many questions now all Goldfinger okay I jut doubt it a couple notes hang on let me find them so there's always new things to learn and if you recall we had a great earthquake session and we were talking about evidence for great earthquakes along the Cascadia subduction zone and the evidence was Brian Atwater finding evidence for sudden land level change on shore and then Chris Goldfinger with marine vessels and sending cores into things called turbidites which are deposits from underwater landslides offshore and those are the two ways that we can read the history of how many big earthquakes we've had in Cascadia and I shared with you that the evidence that Atwater has and the detailed evidence the Goldfinger has doesn't totally match up as far as dates are concerned so that's still kind of a work in progress but Goldfinger has brand-new evidence and he presented this in December at the big a GU meeting the american geophysical union meeting a huge geology meeting this is before the virus December of 2019 and he presented a new paper that says he has eight seven new cores in turbidites just north of Cape Mendocino underwater and seven new cores with turbidites just south of Cape Mendocino in other words he's right in the vicinity of the triple Junction looking carefully at underwater landslides he interprets from earthquakes here with Cascadia and here with the northern segment of the San Andreas Fault and he has found these unusual two layered turbidites again turbidites are underwater landslide deposits and his interpretation of his unusual two layered turbidites is that he's starting to think he has evidence for a Cascadia event off the coast of Southern Oregon in Northern California I'm going to say it triggering an earthquake on a completely different type of a plate boundary north of San Francisco he says I've got evidence for eight of these things eight earthquakes that happen on Cascadia and then followed shortly by northern San Andreas Fault this is brand-new this is doomsday stuff this is talking about our two biggest earthquake faults along the entire west coast of North America interacting and triggering each other again his evidence is interpreted as Cascadia if it's if it's self enough and big enough then kicks off a transform earthquake in the northern San Andreas Fault system as usual we're all sort of skeptical and science by Nature and this is a brand-new set of ideas I think he first proposed this in 2008 and now he's got this new paper in 2019 so we'll see where that day to go to that if it's goes and we're continuing work happens but is there a connection is there a potential link between Cascadia quakes and San Andreas Fault quakes it's possible according to gold Chris Goldfinger out of Oregon State University the transverse range it caused by the shear Cosmo okay you're just answering somebody's question James yeah there's some revert bolts and the only a basin that's responsible for creating the the oil fields there the oil reserves and so there's reverse faults and the Elliott basin basically as it's kind of a bend in the San Andreas Fault here near Los Angeles and so you can imagine this piece of continental crust it's writing in the Pacific plate having a hard time getting around this bit since the San Andreas Fault is not straight there's compression of this crust and so we're shortening the crust and the Northridge earthquake in LA in 1994 was not on the San Andreas Fault proper but was on a blind reverse fault or reverse fault we didn't even know about that's how you can get pretty discouraged if you really get into the detail of what we know and what we don't know about this system while we're at it it's more than just one fault so the Hayward Fault is what that guy was talking about with his old computer the Hayward Fault there's all these branches coming off of the main San Andreas even the Walker Lane and Owens Valley there's if you think about a long enough time frame it's appearing I used to work with Jeff Lee here and Jeff would be mapping down in the minor deflection and all these little valleys near Tonopah and Hawthorne Nevada sending students down there and making new geologic maps and they're seeing that some of the plate interaction some of the transform plate boundary activity as being gradually transferred over to Eastern California and western Nevada and from his work and other work it looks like maybe in the next few million years we'll have a transfer or a jumpring of the position of the San Andreas Fault I don't know that much about that but that's the role of the Walker Lane and again I'm really I'm really all over the place but we have had some earthquakes just since we've been doing these live streams there was one in San Francisco sorry there was one in the Salt Lake City area there was an earthquake in up by Stanley basin in Idaho there was one in the Walker Lane and I've gotten you know tons of emails and I'm sure most geologists have gotten questions about that if you take the time to look at all these events all these earthquakes and have a big enough sample size and and magnitudes and you kind of plot all that in your mind we are we naturally want to you know find some trends and some patterns and say that things are getting worse or we're leading up towards something and yes we cannot forecast earthquakes but statistically there's nothing unusual if you look at a grand scale of seismicity over the last hundred and thirty years as long as we've been studying them Gary how thick are the list of fear plates along the San Andreas Fault about the same on both sides generally yes lithospheric plates tectonic plates in general are 100 kilometers thick 100 kilometers they're about 60 miles down so that's maybe the simplest thing to say is that the San Andreas Fault is not just a normal crack that goes down ten miles it goes down a hundred miles and is a significant tectonic boundary I'm way back at 10:14 and you're at 1022 so I'm about 10 minutes behind oh good lord yeah let's dude let's do 10 more minutes and we're done this is fun but I mean whatever yes Colin creep in Hollister oh that was a clip I wanted to show I guess it was in one of those yeahthere's famously there's curbs in streets in hollister that are just slightly offset there's sidewalks that are just slightly offset like not broken cleanly like the fence thing but just gradually bent so the variability along the trend of the San Andreas Fault rock-type wise geometry wise there's so many variables that that we're not doing with the guy on the with the old computer said what did he say by night yeah I'm confident by 1980 we'll have be able to forecast earthquakes well here we are I don't know if we've made a whole lot of progress since then to be honest that's maybe not fair to say that but as a teacher that's kind of how I presented major leaps forward up here by the way when they're making that film down there and that showed that footage from Alaska that was a great earthquake that was a locked zone becoming unlocked and tsunami nobody knew anything about those great earthquakes those mechanisms until Bryan Atwater did that work in the mid-1980s captain Ned says come on Dutch and others forecast quakes captain with all due respect I just don't think those guys are being honest and true to all the evidence that's out there and I'm just trying to report the data that we have let's not let's not is there any evidence of slow earthquakes along the San Andreas interesting question Oscar I know of no evidence of that so we did in a session with Walters Iligan slow earthquakes in the Cascadia subduction zone and there was something going on below the lock so in kind of a transition zone where there must be some fluids or something I know of nothing like that on the San Andreas I'm scrolling backwards now could the position could the Pacific plate in Southern California drift into western Arizona causing the volcanoes drift into western Arizona but to get volcanoes Charon we either need subduction where two plates are colliding or we need massive extension like the Basin and Range province and we have neither currently with the San Andreas and I don't see that changing even if the San Andreas shifts over to Eastern California it's still going to be transformed in nature so no I don't see new volcanoes or a major change in the type of plate boundary happening in the next few tens of millions of years smiling llamas how many discrete sections of the San Andreas Fault that slip at different times I don't have a great answer maybe somebody does I'm just familiar with 101 textbooks that show half a dozen different segments there may be a dozen different segments that have different character and different histories I will say I'm pretty confident we've made significant progress in inventory in past earthquakes you know that's something that I like to talk about where we to be able to look to the forward at all we need a nice law just like in anything history is going to teach us you know how does how to look to the future so with all those trenching efforts and other investigations we know a lot more about past earthquakes going back thousands of years so that's progress oh there's a lot of Dutch talk okay I'm open to everybody I'm open to everything if it's honest scientific work can't cherry pick what you want to talk about Colin ba husband oh you're answering somebody steve has a fault slip ever been filmed as it happened interesting question on the San Andreas I assume you mean no I I think I would have seen it by if it has happened if somebody knows of that I'd be very interested but it makes it interesting that's really an interesting question like god forbid there's a big earthquake in I don't want to say a town but there's a big earthquake in a place on the Senate dress and there's you know real-time traffic cameras or something and you can see that off-ramp get offset by 20 20 feet hopefully at 3:00 in the morning or when nobody's out there Wow yeah amazing great question never thought about that before let's do three more and we're done liz is making breakfast or lunch brunch smells like eggs and cheese to me Bradon how has the mouth of the Colorado River been affected by the movement of the Pacific plate so there's lots to look at on this map and I don't use this I love this map but it's got too much glare typically for our camera the mouth of the Colorado so the Colorado today the Colorado River is coming through the Grand Canyon Lake Mead dams of course the Colorado the mouth of the Colorado emptying into the Gulf of California both mouths of California mouth of the Colorado River going into the Gulf of California what's your question again how is the mouth of the river been affected by the movement of the Pacific plague I don't know but I can guess the as we continue developing the San Andreas Fault but with that with Jenda snipper she was showing you that this whole gulf is younger than ten million years maybe even younger than five million years old and so we've kind of unzipped this gulf meaning we're continuing to lengthen this body of water as we now we're getting into details I don't know so kind of a half half-baked answer in honor of the Graduate 1967 one of my favorite movies half-baked is that then maybe the mouth of the cola Colorado was was further south when the Gulf was smaller but as the gulf enlarges the mouth of the Colorado has enlarged migrated north as well but I know of no major shift like the Colorado river used to flow like that way into Mexico and now has been captured by the Gulf I don't know of that as a thing Kile house one of my favorite USGS geologists dr. jerk on instagram is the specialist with the Lower Colorado he'd have an answer for you Serena can the pressure build up prior to breakage be enough to cause metamorphism I don't think so even though we're talking about a lot of pressure and hundreds of years we need way more pressure over millions of years to truly develop metamorphic rock through dynamical or burial metamorphism thanks for the question it's past 10:30 I gotta quit I gotta quit Michel Stefan oh you're back you couldn't handle yesterday and now you're back God did an amazing job creating his earth thank you a toast to all of you including Michael thank you for sticking with us to the end of this extended program here's to your health the health of your parents the health of your grandparents if they're still with you the health of your children the grandchildren your extended family and friends here's to us I won't see a Monday Tuesday night at 6:00 p.m. Pacific time love to have you back it's supposed to be a rainy one so I'll probably be inside here again going to John Stockton's house Wednesday night George Beck petrified wood gingko Park Central Washington University Thursday Israel Russell the first geologist making elaborate geologic maps back in the vintage of George Orda Smith I want to learn about him I don't know anything but somebody help me email me amazing links to his original work so thank you for that Saturday morning hoping to go out and do a field trip in our valley here for you it's kind of a crapshoot it's hard to call the weather and especially the wind a week out but we'll cross our fingers and then next Sunday morning I've got to do my homework but enough people are asking about paleomagnetism but I'll try to deliver something for you all I'm sorry if I didn't get to your question I know there were a lot there but I did my best to reach as many of you as possible regardless of your age and your background I salute you I love you I'm glad you're with us not only tonight not only tomorrow night but Tuesday night when I see you next thanks for tuning in I love you goodbye

Channel: Nick Zentner

Views: 45,238

Rating: 4.9112988 out of 5

Keywords: California's San Andreas Fault, Carrizo Plain, 1906 San Francisco Earthquake, clockwise rotation, Tanya Atwater, Chris Goldfinger, Baja-BC, Nick From Home, Nick Zentner

Id: 6G8oFfM3df4

Length: 108min 58sec (6538 seconds)

Published: Sun Jun 07 2020