WHERE THE FAULT LIES, Segment Two: From The San Andreas to The Calaveras Fault with Brian Hackney

welcome back I'm science editor Brian happy we're above point raise but point raise didn't all issues to be below us point race moved up from where it was formed in Monterey it's now anchored to West Marin and those rocks near Palo Alto they used to be above Santa Cruz so this has been transported up here by the San Andreas San Andreas Fault that's that's correct this movement happens in one of two ways so dramatically you'll never forget it or so slowly that nobody even noticed it until 1956 sikri Ponte folds is actually a very rare thing so let's head south to San Benito County and drink a toast to the place where creep on a fault was first discovered hmm that is wonderful it all began at the duros vineyard ten miles south of Hollister of all the places to pick a century ago somebody managed to put the building down right on top of the San Andreas Fault oh my god is that it's where they first discovered that faults creep yeah that's where the fault line runs right through the building back in the 50s they knew something weird was going on here that wall was attached to that wall doorways were bent the floor was fractured the ditches outside didn't line up this is the doorway from the Pacific plate you step through it and you're on the North American plate and you always tell people what it's not my fault slowly but surely the two halves of the building are sliding apart Pat DeRose had to cut rebar to separate the walls and when I got to the last piece everybody handed me the torch and says you're the boss you cut it so the two halves of the winery warehouse are free to go their own separate way and at the back of the building the San Andreas has kicked through and it heads north but it gets complicated because this kind of creep is now transferred on to faults calaveras emerges from the hills east of here it heads north and the Calaveras is tearing apart a town more quickly than anywhere else in the world I know I was born there I grew up at this fork in the seismic road in Hollister my biggest fear wasn't being killed by a quake but being killed by my sisters little did I know I lived in the Creek capital of the world well excuse me ma'am ma'am ma'am do you know that the Calaveras fault is just blocks from here no why do you know that god thanks for doing me quits right let's go ask the man let's go ask your mother gram do you know there's an earthquake fault right out here no I got a move yeah take you back with your daughter go straight for the Calaveras slices Hollister and no town is being ripped more quickly than it is here wow that's stunning look at this look at this day and this my dad by the way look look look I turn here look at the offset in that sidewalk one sixth Street look at how much the curb has been split look at that did you know I remember when it was a lot straighter than well it is neat because it's very special it's really rare in the world you know that sidewalk we saw was from 1911 and so we have a long period you know that we actually can see the change you can follow the fault out of town by following these sag ponds low points formed by the Calaveras the ponds lead to the fastest-moving part of any fold in the Bay Area we're emerging shy signal now we're in the hills east of Gilroy saw the faults right out here yeah follows that pond to this pond there's a reason these things span the Calaveras here it's creeping fourteen or fifteen millimeters a year that's a little over half an inch yeah that is faster than anywhere in the Hayward Fault yeah definitely so fast the geologists keep an eye on it with these the USGS set down these concrete markers in a perfectly straight line right across the fault in 1972 and Danny and Heidi and I are standing on the markers except Danny's not standing exactly on his marker Danny take a step on your marker he's on the other side of the fault and that's how far north it's moved since 1972 about 17 inches north we had a one the part of the bolt that produced a spring of quakes in the 80s the northern calderas fault from Calaveras Reservoir to Danville can produce large earthquakes like how large has learned probably a seven Wow up through Sunol Valley across 580 near the 680 interchange and arrived in Dublin we're at the intersection Foothill Boulevard now Costas and now we're here on the map this is where that we're basically pretty much where the fault is and the map shows the folk goes right through that are you aware of the fact that the Calaveras fault like goes through the building no but they are aware of the periodic quake swarms that rattled the San Ramon Valley and lift up Mount Diablo that's being uplifted to 3 millimeters per year it's going up and to show you how close the fault is to a lot of houses Keith Annette WAV Keith Keith and I are standing here on top of a hill lift it up by the Calaveras fold and look at how close these houses are to it did you know the fault was that close no I didn't really I knew it was close but not in my backyard practically would you have a problem with living in one of those houses that close to as well as a geologist it'd be great I'd get a front-row seat I'd be the first one on the rupture and it all happens because of lava that's squeezed out at the bottom of the ocean moves plates around the plates collide with the continent raised mountains breed faults it's that movement on a massive scale that makes strike-slip faults like the san andreas so rare because they eat themselves after all everything west of the san andreas fault system is heading north for a watery than fiery grave in the Alaska Trench so goodbye San Francisco goodbye San Jose goodbye Los Angeles California rose like Atlantis from the bottom of the ocean and to the bottom of the ocean it's destined to return one small step at a time we'll return to after a break it was March 11 1933 camera and crew were on the Paramount lot to film International House was a comedy starring WC Fields they were rolling on one of his scenes as the second deadliest quake in California history struck 46 take one action man you probably saved my life now what can I do for you take us to Shanghai all right now in 20 seconds 115 were dead almost all of them killed in old brick buildings it's been a problem from 1933 in Long Beach to 1989 in Loma Prieta it's the buildings that kill is the buildings that cause the worst effects this is a dormitory Peter Univ has travelled the globe trying to make buildings safer this is one way of doing it it's a very efficient way of doing it not necessarily the prettiest these are the older large buildings lots of people live in them built without any earthquake regulations or minimal regulations going back to the 20s and 30s I think if they're concrete buildings they represent some of the worst risks in San Francisco and in California hard to imagine what happened in Kobe Japan could happen here but they're on top of a fault just like we're on top of a fault the difference is theirs snapped if Kobe taught me one thing that is that in a few seconds you can lose half of the value of the city we saw buildings pancake we saw buildings collapse catastrophic Lee and kill not one or two lives but thousands of lives that has happened in every large earthquake throughout the world and these buildings are not some of them are not any better than the ones I have seen collapse in Japan in the Philippines in Southern California and elsewhere buildings are the deadliest problem but they won't be the only problem in a big quake where what I least want to be I wouldn't want to be in the tube underneath San Francisco Bay on BART a magnitude seven could wipe out parts of Bart for a long time how long could Bart be down following such an earthquake a minimum for a major earthquake with no retrofit to be two to three years these elevated sections of track just aren't strong enough will have broken piling will have structures leaning Bart is doing everything we can to identify those risk and to fix them serious damage on the gorge you'll be glanced at oh the extra box to cross the bridge have paid off 1989 was a wake-up call that let us know that we needed to go farther we've got the risk way below what it was 15 years ago let's hope so after all what would Golden Gate Bridge did alright the Bay Bridge was almost brought down by a magnitude six point nine that was centered almost 60 miles away now if we had the night the 89 quake near San Francisco instead of way south of here you would have a completely different earthquake and a lot of buildings would have collapsed it's certainly possible to retrofit old concrete structures like this one but there are no requirements to do anything about those old concrete buildings it makes no sense to me because we have the Golden Gate Bridge we're strengthening it currently it's built in the 30s on the other side we have the Bay Bridge also built in the 30s we're strengthening it so the question then is why aren't we strengthening some of the dangerous 1930s buildings with high occupancy it's a good question especially because seismologist believe that quake activity is becoming more robust in the Bay Area and as David Schwartz pointed out we are the boundary between the Pacific plate to the west and the North American plate to the east the plates are moving past each other at about 48 millimeters a year you know two inches or so that movement which seems very small and it is is divided onto the different faults now if you take 200 years or 300 years between these large earthquakes you can see that little few millimeters a year builds up continues to increase so finally after after 250 years on the Rogers Creek fault you've built up 2 meters or 6 feet of slip boom now we're sitting here in 2004 the last really great earthquake was in 1906 but if you look at the history of earthquakes in the 20th century and you can pair it to what happened in the 1800s there is no comparison the 20th century was quiet 1906 was so big it fundamentally it punctured the region it led all the stress out it relaxed the crust essentially turned the seismicity off so we went through the 20th century all of the infrastructure developed the population increased and it was seismically a quiet time there is no written record of California quakes before 1776 but there is a record in the geology it shows that 300 years ago the bay area was regularly shaken by large quakes what happened during that period of time is what lies out ahead of us starting sometime in the late 1600s the southern Hayward Fault - Northern Hayward Fault the Rogers Creek fault the San Gregorio fault and possibly the northern concord fault all had earthquakes were estimating magnitude 7 or larger and all of these faults have to fail they have to fail because they have in the past they've been slowed down because of the effect of 1906 many of us think that that effect now has sort of wane it has worn off the plates have sort of re-energized themselves they're pushing again we may just reach a point where one of these big faults like the Hayward or the Reuters Creek is ready and poof it's just it's just going to go it's California earthquakes are fun and people say oh I've lived in the Bay Area all my life I know earthquakes I felt big earthquakes we've gone through about three or four big major earthquakes and houses are really instead of pretty well Loma Prieta was just a little taste people haven't felt anything

Channel: TVBAYAREA

Views: 255,152

Rating: 4.8145099 out of 5

Keywords: WHERE THE FAULT LIES, Brian Hackney, San Andreas Fault, Calaveras Fault, Hollister

Id: p4UcmsMAYRM

Length: 14min 59sec (899 seconds)

Published: Fri Jul 01 2011