San Andreas Fault in Mecca Hills: Outstanding Geology At Every Turn

[@shawnwillsey]

Be sure to LIKE and SUBSCRIBE. You can support my educational videos by clicking on the "Thanks" button just above (right of Like button) or by going here: www.paypal.com/donate/?hosted_button_id=EWUSLG3GBS5W8 or here: buymeacoffee.com/shawnwillsey

[@motofunk1]

Not sure how much you have ventured in the area's to the east of Box Canyon Rd. Would be curious your thoughts on this Australia shaped spot at 33.609050, -115.889860 and the mountain range directly south east of it. The spot is much like a dry lake bed and smooth with a hard base. The mountains and canyons to the east are amazing with the way the rains have eroded all the sand away exposing massive rock formations. Google maps does a better job with matching true color, Apple maps has better vertical relief of the areas.

[@danacataldi5119]

I grew up in Southern California near this area. My mom grew up in Rigby Idaho. We went to Idaho every summer to visit relatives. I remember looking out the window of our camper thinking that everything looks the same, brown, brown brown. Now I know how wrong I was. This is wonderful to revisit these areas with you and appreciate the geography and the history behind the brown hills.

[@briane173]

I grew up in L.A. and the only fault that got anybody's attention back then was the San Andreas -- at a time when plate tectonic theory was a baby and there was little acknowledgement that the San Andreas was a plate boundary. That was until I experienced two earthquakes while living in Long Beach -- the Borrego Mtn quake in 1968, and not three years later the Sylmar quake, which was the worst quake I've experienced before or since. We were a good 50 miles from the Sylmar quake's epicenter and yet we had _intense_ shaking, which awakened me as to why my dad had our house framed with steel I-beams. I found out like 50 years later that the Newport-Inglewood fault ran right by our house, which ruptured in 1933 and flattened much of Long Beach. After Sylmar I got really interested in seismology, but I didn't have a good grasp of geology until much later in life; what I've discovered about California and the places I'd lived at there got me totally hooked on geology and how CA's geography came to be, and it is absolutely exhilarating.

[@anniehamilton-gibney9691]

OMG, I have only ever been to California once in March 2018 (I am a Brit living in Portugal) but I went there !!! We spent a day visiting Slab City, the Salton Sea and we took a walk along the San Andreas fault line at 1000 Palms Oasis. I remember stopping along that road with the friends I was with as we tried to figure out the geology there. It was totally amazing to be able to hear about how those hills were actually formed all these years later, rather than just our guesswork. Wish I had watched your film before I went, we would have spotted so much more detail. So happy I am now one of your 'team' !

[@shawnwillsey]

Welcome aboard, teammate.

[@thedudeimbibes46]

It’s great to hear of your adventures in the Coachella/Imperial valley. Much of my youth spent in same area and I wish education would’ve included geology and possible field trips to sites that Shawn details. I always got a kick out of the ancient ocean waterline still visible high above the valley in the rock walls.

[@Dragrath1]

Hey while you might have missed detail on your trip you should be able to find cool stuff more locally as Portugal from what I am aware of as part of the Iberian plate also has some impressive ongoing dynamic geological history too there have been some major historic earthquakes there even Tsunamis due to faulting off the coast related to the Azores Gibraltar fracture zone and some minor volcanic fields in parts of Spain. From Nick Zentner's Baja BC A to Z series I remember one of the guests talking about a prominent S shaped ophiolite folding from the former volcanic arcs that formed the Iberian plate. You also have the Pyrenees where the Iberian plate slammed into Eurasia or ratehr what would become the modern wester margins of Eurasia during late Cretaceous time. I'm not too knowledgeable there on stuff so I'm sure that is the tip of the geologic iceberg of sorts. Its a far cry from the British isles which have had a bit of a tectonic lull in activity since the break up of Laurasia during the Paleocene finished. I recently learned from a curiosity driven research binge of mine that the Irish Sea is a Graben while the islands of Ireland and Great Britain are both horsts from that continental break up. Technically because the Graben block is dropped more towards Ireland I think it might be classified better as a half Graben but the point still stands. Basic ally if you go back far enough everywhere there is going to be some cool geology.

[@ericclayton6287]

I agree with Dragath1. You will find rich pickings all over the Iberian peninsula. Have all the processes we do in the western US.and it’s often well exposed.

[@saywhat8966]

There is great geology everywhere but vegetation hides rocks from view. Spain should be fascinating. Years ago I was fascinated by the multiple hills next to the Persian Gulf in Iran on Google Earth.

[@delilahboa]

Fascinating Shawn, I love the way you ‘read the rocks’ ❤

[@kestenyi3873]

That Roadside Geology book is really fantastic, so much explanation and detail for every part of the area. It was fun seeing things they pointed out and discussed in this video too, like a companion tour to the illustrations. Thanks!

[@davidk7324]

So cool. Your teaching style subtly nudges viewers to work out what you are showing us. I wonder how many viewers said "schist" to themselves (or out loud). Thanks Shawn.

[@edwardlulofs444]

Since I taught Earth Science to freshman I did recognize the schist. To help make the science terms more memorable I used colorful language. So when I saw that rock I said oh that looks so schisty.

[@morebirdsandroses]

What, me? I'm afraid I never get too old for silliness. Sigh.

[@markshietze4783]

so thoroughly agree , sir ... he is awesome ... ...and I had to say it several times till he spelled it again

[@briane173]

@@edwardlulofs444Since minerology is a useful discipline within geology, it's okay to use 'salty' language.

[@edwardlulofs444]

@@briane173 thanks. My physical science students didn’t complain.

[@jennifershipp2599]

Thank you for sharing all these interesting areas with us. Our world is fascinating if we stop and look closely. 😊

[@marksinger3067]

Teen in the 1960s here learning more about the earth’s structure every time i watch another video from you and the other geologists explaining rocks.. Go to Devil's Punchbowl near Pearblossom for more San Andreas Fault evidence..Thanks again for what you do..

[@pinkpyjamas-ey6rw]

Great stuff! Am learning so much, just sitting here in my cosy house on a dark and wet Saturday afternoon in rural Perthshire, Scotland!

[@williamlloyd3769]

SR-14 aka the Antelope Valley Freeway is my favorite way to see the San Andreas fault at the freeway road cut. Impressive to see the folded rocks as well as the other visible features. PS - Also gives me an excuse to stop by Vasquez Rocks Park in Los Angeles County. My kids always liked seeing where Captain Kirk fought the Gorn. Too much fun!

[@briane173]

That road cut has some of the best exposed folding anywhere. Mecca Hills might be the next best place.

[@Rachel.4644]

Neat to see smaller slickensides, and closer views. I always learn from your videos, particulars as well as concepts. (And the sun is cheery on this 16° snowy morning.) Thanks, Shawn!

[@Riverguide33]

Wow…the things we take for granted when we drive. Thanks, Shawn. 👍

[@debdiemer3749]

Fascinating! I can see some similarities in the slickensided in these rocks to some of the rocks in Bighorn Sheep Canyon near Canon City Co! Thank you!

[@curtiscroulet8715]

I've been through this Box Canyon (there are others in SoCal) many times. I never noticed the slickensides. Odd as it may seem to you, I've always wanted to see slickensides in the field. I've never identified it. This will help.

[@dudeonbike800]

That exposed section of fault plane should definitely have a road sign! It's just too convenient to let so many miss out on that feature. Then again, if it were marked, it would probably be in terrible shape by now. I dare not think of the vandalism that would occur there. Which really promotes "Roadside Geology" so only those who are interested and care will know of its existence.

[@edwardlulofs444]

I drove that road for the first and only time in early 2023. I share your astonishment with that area. But I was able to see a tiny fraction of what you explained. So this episode was very informative for me. Thanks.

[@Selah-dl3ef]

It is a wonderland.A rock structure wonderland.🤔Thanks Shawn.😘

[@dennisyardn1ten238]

I've been through Box Canyon a couple of times and stopped in several locations to look at the folded layers. But I didn't see that wonderful fault plane. I was taught (in the 70s) that the fault plane lines were "slickensides. " That road is a very good short cut from I-10 past the north end of the Salton Sea and southwest to Borrego Springs and up the mountain scarp to Julian. Lots of geology here in So Cal.

[@Fouqueria1]

I LOVE your videos! You are a great teacher! Thank you for sharing your knowledge! I really enjoy every single one of your videos!

[@jeremiasrobinson]

I've been pretty close to that spot. It is a fascinating area.

[@valoriel4464]

Thx Prof for another interesting geo-ed adventure . ✌🏻

[@jackmcmichael3560]

That was a fantastic video being from southern California I now will be heading over there when we are done with the rain and rewatch this video and check it out live thank you for making these videos 👍

[@briane173]

I will be the first to admit that Coachella/Imperial Valleys are probably my least favorite areas of California; but it is so geologically active I will have to visit it with a fresh set of eyes. Last time I was down there was in 2005 when my dad owned a couple houses in Desert Hot Springs. Wasn't until about 5 years _after_ I visited that I found out why there are both cold _and_ hot springs in DHS -- a branch of the San Andreas Fault runs right through the center of town, right near Miracle Springs Resort. Cold springs on the North American Plate side, hot springs on the Pacific Plate side. It's worth another visit just to take the tram back up to Mt San Jacinto, and to follow the San Andreas from DHS down to Salton Sea. Don't even need GPS; just follow all the sag ponds along the boundary. There's dozens of palm oases sitting right on the fault with plenty of water.

[@jeffsiegwart]

Great video! I enjoyed learning about this area. Thank you.

[@thormusique]

Very cool, cheers!

[@craigkeller]

Geology rocks! Thank you for the tour, really beautiful!

[@kevinmurphy1884]

I drive through this area as a shortcut instead of going by indio. it really puts things in perspective as where we are in the food chain. great video. it's great for understanding this great planet.

[@johnramirez5032]

Geographic processes are reall hard to invision for me because they are so large. Of course not knowing what under the ground doesnt help. I love the way zoom out and zoom back in showing the distence. It really helps me get a better idea how the process took shape . Im also facinated with gold deposits and how they formed. Jeff Williams almost always discusses geology. I think we live on a facinating planet and i want to know all about it. There is just not enough time and resources to do so. Thank you for your time and attention to detail. It is geologist that have found the largest deposits of valuable raw materials we use today. The mapping of faults of course is very important to all of us. Geologists are underrated as to there contributions to society. Thank you sir for all your work.

[@SandCrabNews]

Have you seen the Fish Traps Archeological Site?

[@doctorofart]

Great video. I learned a few new terms. I understood that a syncline come from the term sine as in sine wave because of the way you put your hand up to illustrate the term.

[@edwardlulofs444]

I didn’t know that, thanks.

[@seekingthetruth304]

And....an "Anticline" is the general shape of an "A" 👍 It's also "Anti"....like opposite (shape) of syncline ~~~~

[@hamidrezasepahian7608]

Your explanation in all videos are excellent, eloquent and fluent, yet simple

[@brucedymock6635]

Just watching this really great takes me back to geology 1 in 1970 thanks very interesting as I’ve heard all the SA fault stuff of movies but great to see on the ground

[@toughenupfluffy7294]

This is amazing to see the San Andreas fault in action, its effects visible in the rock! thanks for this eye opening video!

[@michaelmckeag960]

We drove through Box Canyon yesterday, not for the first time, still need to visit when not on the way somewhere else . Thanks for the glimpse into the geology. Hiked Ladder Canyon once on a geology field trip, worthy of a return visit too.

[@julieinthedesert420]

Thanks for this. I love learning all I can about the geology around where I live. ❤❤

[@brandohi]

Thank you @shawnwillsey for this awesome video! You are one of the reasons Geology has impacted my life and I challenge myself to become a geologist. I currently live in the Coachella Valley and I’m so blessed to see all the features surroundings. Thanks❤️

[@davec9244]

thank you stay safe ALL

[@loopbraider]

I've been through Box Cyn so many times, loving the cool shapes and features of the rocks but looking for plants! Lots of really neat desert plants around there and yes, Ladder canyon is super-fun to walk and climb through, magical! You should definitely go back there so you can tell me about all the geology we didn't understand at the time! THANKS for your videos, Prof. Shawn.

[@VegasCyclingFreak]

Interesting stuff. On the Red Rock Scenic Loop just outside of Las Vegas, there is an area where it is said that you can stand directly on top of where two tectonic plates meet. It's known as the Keystone Thrust Fault. I wasn't able to perceive it very well, but I'm also not a geologist. All I saw was a lot of decomposing sandstone, which is everywhere in this area. I guess really needs to be looked at more as a region as opposed to one specific place.

[@seekingthetruth304]

(As a geologist) being able to stand on two tectonic plates near Vegas doesn't make sense to me, because the plate boundary between the North American Plate and the Pacific Plate is the San Andreas Fault, which is not that close to Vegas. I'm going to look up that fault you mentioned though...👍

[@VegasCyclingFreak]

@@seekingthetruth304 We have some faults running thru the Las Vegas valley but they don't seem to be very active. The bldg dept puts us in a certain seismic zone too (can't remember which one it is), so we have to do stuff that is a little more stringent that you might think. I work in consulting engineering, but I am HVAC engineer... don't know all of those specifics.

[@davidedgar2818]

Thanks Shawn this is one of my favorite spots to see the fault.

[@GailVaught]

Relearning so much from you Shawn. Geology is much more fun when you have field trips to go along. Wish my instructor had arranged field trips when I was in college in Vegas. It is such a rich area for geology.

[@scottkemp22]

I would like to see and understand the earth movements on a more macro scale. I would like the systems at work explained.

[@edwardlulofs444]

Yes, I like structural and tectonic geology also. But good grounding in the basics is important also.

[@Dragrath1]

Yes I also find Geophysics fascinating. Especially since Geophysics is seems to be undergoing a much more dynamic perhaps even paradigm shifting view in part due to newer technologies helping us probe the Earth such as seismic tomography and precision GPS data etc. From a big picture perspective Nick Zentner's A to Z Baja BC series was really helpful for introducing much of the newer emerging field developments as was the Crazy Eocene series. There is still a lot of unknown inconclusively resolved stuff but continental faults definitely seem to be more blurry less defined than conventionally pictured more a region than a discrete boundary. Its a bit more defined with old cratons or large well anchored rigid batholith complexes capable of deforming as rigid bodies still but the relatively young unsettled accreted terrains seem to deform more differentially via a complex network of faults. I can't help but notice some parallels between ice sheets and ice shelves where durable continental crustal blocks are like the anchored ice sheets or large ships floating in the upper mantle & the oceanic crust that forms the exposed skin of these deeper "plates" and the other areas of continental crustal material which are a relatively thin veneer on the more or less oceanic/mafic mantle + oceanic crust. It seems its more this oceanic crust and underlying mantle currents which form the system of convection cells which drive plate tectonics with subduction zones being where downwelling drives crust into the mantle through a complex series of remineralization down to the Core mantle boundary where they seem to pile up. The remineralization in these sinking slabs can generate compositional hot spot inter-plate volcanism as lighter materials carried down into the mantle get forced out of the rocks and can reduce the density of the overlying mantle causing it to rise. And these colder denser slabs which appear as slabs and slab walls of fast sheer velocity regions seem to eventually reach the bottom where they pile up and possibly are responsible for the blobs of anomalous density low sheer velocity zones, at least two of which are absolutely huge the size of entire continents, where the normal hot mantle plumes seem to originate. There is some cool stuff about those (thermal) mantle plume hot spots which seems to indicate that they not only do have their own independent motion but tend to over geological time migrate towards and feed into Mid Ocean Ridge systems or emerging hot spots have even in the past lead to new Mid Ocean Ridges systems forming though said mantle plume heads might be a symptom of those larger tectonic reconfigurations. Either way these two kinds of upwelling features plumes and upwelling MOR systems seem to be connected and form the upwelling counterpart to subduction in the convective system which connects Earths outer liquid core to its surface. And then there are the processes in the outer core where the hot low viscosity molten iron forms vortices and currents that perhaps more aptly could be considered analogous to the storm fronts and large scale ocean circulation currents of Earth's atmosphere and hydrosphere. The net effect of precipitation with these outer core storms is that the solid inner core appears to be getting built up by what are effectively iron snow storms. These storms and the currents they generate in turn seem to be responsible for Earth's magnetic dynamo in the sense that the latter is the result of the net global circulation of these flows. Thus the more stormy the outer liquid core the more potent Earth's magnetosphere will be with the net field orientation depending on the specifics which we can study and or model via the nightmarishly complex system of differential equations of Magnetohydrodynamics (Naiver Stokes equations for fluids plus Maxwell's equations for electromagnetism). Its so complicated and fascinating!

[@edwardlulofs444]

@@Dragrath1 yep. A lot more complex and interesting than when I was choosing a career 40 years ago. I wish that I could find such lectures online. I knew Nick Z when I worked at CWU. Great guy. I have been trying to follow his talks about the Baja to BC connection. It looks like there is something there.

[@oscarmedina1303]

Thanks for Mecca Hills video.

[@margaretgorski7947]

Thanks Shawn!

[@davidmccann3535]

Thanks!

[@shawnwillsey]

Thanks for supporting my geology videos.

[@paulproctor5555]

Thank you Shawn. Always a treat to sit in on your field trips.

[@arthurma8072]

Excellent instruction as always but now I have to revisit to see the things I missed previously great thanks 🎉

[@alpineflauge909]

world class content

[@barbararoberto1258]

Very interesting, fascinated with the faults and you made it easy to understand how they work, it is awesome so I subscribed.

[@snojoe10]

Thank you Shawn for another great video full of interesting geologic content. Going to have a much more interesting field trip next time I visit Palm Springs.

[@morebirdsandroses]

This is so gratifying. I had been in that area often in my teens and 20s and having at least a grain of insight into rock/fault is owing you a big thanks!

[@1607rosie]

Shawn as a prospector, I’m very interested in the geology of the southwest. I enjoy your random road cuts. I find myself looking at te road cuts myself locally. I watch your videos over and over trying to retain every thing your teaching. I’ll be happy if I can differentiate the rock types when I come across them.

[@TheEarthMaster]

Great video!

[@berthaduniverse]

Thanks Shawn, great material for us socal residents. I hope you eventually get to Garlock and Red Rock Canyon areas.

[@sharonlobo7930]

Great stuff! Thank you as always!

[@LisaBelleBC]

Loved it! It’s awesome to see how you find the little details that we would have missed! I can’t say it enough but thank you thank you thank you for taking us places we will never get to ourselves.

[@Celeste-in-Oz]

Professor Willsey on track for 100k 🤘

[@gsmith9531]

Thank you for another GREAT field trip!

[@jmanxoom]

This is so cool. I'm from this area, fascinating info in every video

[@annehopkins3393]

Thanks for another fabulous video

[@carlschissler]

"Pro Tip" for the starting google earth zoom sequence: record it in reverse (from ground to space). That way the detailed data is already loaded and you will get less pop-in. Then reverse it to zoom from space to ground in your video editing software.

[@robertwest6350]

Love hiking there!

[@vintagelady1]

I really do find this fascinating, thinking of all the things these rocks have been thru & "seen." I'd say "If these rocks could talk what stories they'd tell," but they do seem to talk to you. Thanks for translating for the rest of us! And may I say that geology has the most colorful vocabulary: unconformity, nonconformity, & my favorite, orocopia schist.

[@GracieValenti1]

I really enjoyed this vid! Thanks for making it. I grew up in Southern California and was always told we could see the San Andreas fault off to the side of the 14 freeway going north into the Antelope Valley (Palmdale and Lancaster). We got a kick out if it when we were kids and I vaguely remember something about "The Palmdale Bulge."

[@raktoda707]

Nice touring lecture ! Now I understand much more clearly

[@alanclark639]

Awesome when you think of the forces involved - just in moving the little bit of fault that's visible! And then consider the time it took for deposits to be made then uplifted into mountains, for them to be worn away and chunks to be incorporated as those clasts in the conglomerate. We are so unimportant.

[@DisHammerhand]

I have that book. Very interesting to read. I have not yet gone exploring with it in hand.

[@johnzinkowski6834]

Hi Shawn, As a kid I loved to dig holes in the backyard to look for treasure. That was where I discovered the historical layering of materials and, an occasional old glass bottle. We lived in Boston in "three-decker" apartments so my "research" was not appreciated by the building owners (I did refill my excavations). In any case, I loved geology and eventually took one course in college when plate tectonics was still a debatable theory just gaining acceptance (1960s). I loved the field trips and the opportunity to see what we were studying in class. Unfortunately, I didn't do well with the technical aspects of the science and never took another course. However, I never lost my interest and still collect rocks that I share with family; some of whom also got the bug. I value and appreciate your videos. You inspire me to keep observing and learning. I'll bet many of your students have a blast with your course(s). Another powerful example education where a teacher's expressed love for his subject makes students want to learn. The process becomes more playing-together than anything else. The learning occurs naturally layer by layer in a comfortable happy collaboration. I see the geological connection! Thanks and keep up the great work. John Z

[@shawnwillsey]

Thanks for sharing and your kind words. It's gratifying to see my approach and efforts resonate with folks.

[@michaelburns9172]

Lived in Oaises for twenty years have been allover that area. Very nice to see.

[@loisrossi841]

Excellent, thank you.

[@stevensprunger3422]

I love this, I wish I wish you would do the red rock Canyon right out of Palmdale near the Mojave desert

[@davidkaplan2745]

The Mecca Hills are a fun place to hike, with ladders and ropes to help you get through the canyons. There is colorful ash deposits from the Long Valley eruption, and beautiful banded gneiss sticking up here and there in the canyon bottoms.

[@dudeonbike800]

The exposed fault plane is amazing! At what depth were they when the fault slid and left those striations? And how many years ago? (I assume millions.) So cool to see. And that you can determine direction on some by feeling the roughness differential in either direction is also amazing. Thank you.

[@skyepilotte11]

Every rock has a story to tell. Thx Shawn

[@geoffgeorges]

I spent a day descending from JT when it was too cold to climb and went hiking in a few of those side canyons. There is a Mecca Nevada just north of Vegas where I have climbed. I think it is welded Tuff.

[@briang70]

Great video! For your disappointed students, (and I hope you keep heading north along the fault with more great videos) they will love the road cut on the 14 freeway near Ave S in Palmdale and points north along the fault.

[@ericfielding2540]

That is the first time I have seen slickenlines on sandstone. I have seen them on harder rocks, including limestone. Neat!

[@genethesurveyor]

There is a cut in the hills where the 14 freeway comes into Palmdale near Avenue 'S' that really shows the folding of rock formations dramatically. Have you included any videos of that? It is also an example of the results of the San Andreas Fault.

[@HollyLewallen-Smith]

Thanks for Sharing! ❤ Love ❤. Shared 💜. Saved on KZbin ❤.

[@mapleleaf902]

I hiked there and so interested in your review.

[@JennaFerrari]

When were you there?

[@kban77]

During the Pliocene. :)

[@shawnwillsey]

Early Dec 2023 for this video

[@brendanh8978]

Decades back, my friend and I used to go up the washes off Box Canyon Road to find good spots for target shooting. Same for the wash further south behind the town of Mecca proper. It's such a desolate, quiet, timeless place, usually few people out there. Found some WWII dated .50 cal brass, probably from aerial gunnery training. Chocolate Mountain to the south is still a navy range. Very cool to see the geology interpreted. I knew the SA ran through there, but didn't know exactly how it formed that tortured topagraphy. Hope you visited 1000 palms to the north while you were there. You can really see the fault (Mission Hills strand I think?) where the sagebrush is much thinner to the west/downhill side of the fault due to the fault acting as a dam/aquatard.

[@patrickkillilea5225]

Awesome

[@WA-eg7ft]

Hey Shawn. If you ever need a local to Jeep you around the Coachella deserts I know a guy that grew up out there. He knows it like the back of hand. Upper and lower desert.

[@alanjamest83]

Really cool many thanks

[@LizWCraftAdd1ct]

Love those rocks.

[@Darisiabgal7573]

At 7:10 in this video you present a little exposee on a particular type of fault. Whats interesting about the fault is the uniformity of the alkali scale on the surface. This type of surface would not weather for very long, as you mentioned pliestocene, it probably more on the order of holocene. But the other notable observation, there a section of 6+ feet (2 meters) without any kind of stop/start erosion pattern on the exposed face, we also dont know how much has eroded from the sides, but the side in the foreground looks like its calved of a section leaving a slight different coloration in the underlying rock. But what we dont get from this type of exposure is magnitude, what type of earthquake could make the Earth slide like this and what in terms of modern quakes is this similar to. When me and my family were in Japan a couple of decades ago per chance we were in Awaji, which part of the Island of Shikoku, one of my favorite places to visit. And what sets Shikoku apart is its rather isolated extreme geology, much of these areas are unpopulated because of the rocky soil and extreme cliff faces. One particular place thats famous in movies is Oboki Koboki, but on the day I was there it was white out snow conditions and it was surreal. Shikoku is also famous for the 88 temples, a rather favorite bucket list (but if you manage to make all 88 temples your probably going to live alot longer than you thought). But to live those extra years you might want to consider what is under your feet when you step inside. Awaji itself is rather understated, except in they built a really fantastic bridge, the The Akashi Kaikyo Bridge. Japan as it was settled was first populated by dry rice farmers during the Yayoi, which were later populated by wet rice farmers. This wave of mainland inspired agriculture spread from the island of Kyushu, into S. Honshu and Shikoku and by the 5 th century had reached Osaka region. Wet rice farming requires intense modification of the landscape, and the underlying topography of the land disappears under the farms. Early in the morning of Jan 17th 1995 a mag 7.3 earthquake hit the Kobe-Awaji region along a truly esoteric fault. The largest seizmic motion was to the SW along the Island of Awaji, moving vertically about 1.5 m and horizintally about 1.2 m. The ground motion was severe enough that about 1 meter had to be added to the center section of the bridge. The total motion was about 1.9 meters or 5.1 feet. While the quake was rather shallow and Awaji is relatively unpopulated, in nearby by Kobe-Shin kobe about 6000 people died. While the initial reports suggest this was a new fault or an unknown fault, what was later learned in excavations in Awaji is that the fault was neither new or unknown at least at sometime in the past, farmers had intentionally buried the rather obvious fault line in order to create new feilds. And it is through examining these older shifts that allowed scientist to understand why faults like the Hanshin Awaji Fault had ruptured in the past (The farmers conviniently shielding it from erosion shortly after it ruptured). There are three plates that converge around tokyo region creating a tiny forth plate. Osaka, being southwest of tokyo is on the Eurasian plate which butts against the North American plate northeast of Osaka and the Philippine plate to the South East. What is notable is that the Eurasian rift zone to the east of Osaka is not strait, but curved. Both plates push in the direction of Eurasia but they are pushing markedly different directions. Even in N. Japan were the boundary is rather continuous the subduction faults can violently rupture. But in the interior the various stresses cause faults to develop independently of the plate boundary and these faults may be no longer than a tens of kilometers in length. While it sometimes assumed that Japan is made of Volcanos, there is also considerable tectonic uplift in parts of the country. Despite their short length and low depths these side faults, these quakes can be quite devastating. It worth noting when building in areas surrounding the San Andreas fault that being 50 or 100 miles away from the fault is not an immunity from severe Earthquake damage, these auxiliary faults can literally be anywhere and can appear at any time. In the case of Awaji one farmer built his house on an area of land that was less than a meter exactly above the old fault. Fortunately the house remained intact, but part of the first floor instantly became a deck. Had careful soil surveys been done in the construction of this house, this fault line may have been detected before the quake. These faults Shawn points out cast a warning about populating certain regions without a focus on risk mitigation, because you really dont want to be the fool that builds a skyscraper on a piece of land that moves 8 feet in a few seconds.

[@pookiedust2517]

Thanks shawn

[@orange-rose07]

That's fascinating! I live on an ancient tectonic plate a Ukrainian crystal shield. And I often get curious about places with more dynamic geology.

[@Joel-McConnell]

@Shawn Willsey, do you happen to have any geology videos showing fossil locations here on YT? Thanks! :)

[@charleymitchell5461]

How relevant, was just looking at this area, due to the earthquake swarm.

[@saywhat8966]

Would that be a bad place to be during a Pineapple Express? A live cam set up somewhere to watch and view the fault cliffs would be amazing.

[@Mrbfgray]

10:00 which way it moved indicated by "wake" behind little rocks, little ridge of protected material, appears that slab is going North relative to other side, toward right side of frame. No?

[@Mrbfgray]

Amazing find there!

[@briane173]

It does look like a sinistral strike, which is counterintuitive for this area.

[@tabuleirocmd]

Merci Shawn. A great Diamictite generating context. Would be great to see same characteristics that help distinguish them from glaciogenic Diamictites, imho. Merci again

[@Salted45]

Want to see some folded rocks? Crystal Cove State Park, on the far north end of the beach. It is sedimentary, but beautiful and curled into tight formations.

[@kadourimdou43]

Is the San Andreas Fault, connected to the Cascadia system.

[@edwardlulofs444]

The plate boundaries are (mostly) continuous, so in that sense they are connected. But the San Andreas is a transform and Cascadia is a subduction

[@edwardlulofs444]

So 40 years ago they said “No”. But now they have found “weak” connections. And sometimes not so weak.

[@briane173]

Where the San Andreas fault meets the Pacific, NA and Gorda plates at the Mendocino Triple Junction, that is the most direct "connection" to Cascadia.

[@FishBeWithYou]

Hi Shawn, I found a rock while fishing at Watsonville California Feb 15, 2024. Can I send you a picture and video to identify it? Thanks

[@shawnwillsey]

Maybe take to your local college geology dept. I am currently at capacity with requests. Thanks!

[@FishBeWithYou]

Ok thanks! Really appreciate replying my request.

[@jsmith748]

What is the book you mentioned near the beginning?

[@shawnwillsey]

Roadside geology of Southern California.

[@rtb8346]

Stop # 4 looking at fault plane .If you look at the surface and the imbedded clasts they look like little drumlins. Looks like material has been protected on the left of the clast forming a hump behind the clast .Maybe the unit that is no longer there was moving to the left over the exposed surface . Only a guess . Thank you for the illustrations and excellent communication . Keep up your great work.

[@portia0827]

Could you please do an episode on Japan? The Sakurajima eruption, the new volcano that formed off of Iwo Jima, and possibly a smaller eruption about 100 miles south of Mt. Sakurajima

[@maryt2887]

Thanks, Shawn, for another interesting geology field trip. I must admit that I share the disappointment of your students at the lack of a big crack in the ground. In college back in the 60s, I read (and half hoped for) a prediction that California would fall into the ocean in 1969. Does anyone else remember that? The reality of the fault area is quite amazing, nevertheless.

[@allanegleston4931]

in nt mess of an apartment, i have a book that was published by the old division of mines . it is called the geology of southern ca. had a map at 1 time . showed all the known faults in socal at one time . just subbed .