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Dana King (Host): Alexander McAdie, official earthquake forecaster for the U.S. Weather Bureau, had a nighttime routine.
Alexander McAdie: For 20 years I have recorded every earthquake I have felt. I kept a daily log of earth movements. My custom was to sleep with my watch open and spectacles at bedside. Notebook open to the date, and pencil ready….these were laid out in regular order.
Alexander McAdie: My record of 1906 April came in a frenzy. First shaking was incredibly strong lasting over 40 seconds. A strong aftershock hit 8 minutes later. Another aftershock at 5:25 …and bedlam reigned. More shaking at 5:42 …. And then the fires began.
Dana King: The temblor of April 18, 1906 came out of the sea just offshore from San Francisco…. Moving northwest and southeast at more than 7,000 miles an hour. It had an explosive power equal to more than seven million tons of T-N-T.
Dana King: In this great violent movement of the earth tremors unleashed unimaginable devastation. Streets buckled and humped into undulating waves, and split open in deep gashes. Buildings wood and concrete and glass collapsed, shattered, crushed, twisted, tangled and crumpled so that sidewalks were impassable. Gas lines and water mains ruptured, sewer pipes smashed, electricity gone, trains and trolleys stopped. No post or telegram. People died pinned beneath the wrecks of buildings. And the tremors wouldn’t stop on April 18th there were one hundred thirty five aftershocks. The fires that followed were even more destructive. Without water fire could not be stopped. For three days San Francisco was a blazing inferno.
Dana King: People think of April 18, 1906 as the great “San Francisco” earthquake and fire. But it was really a northern California quake, ripping apart the earth over a distance of nearly 300 miles. It was felt as far north as Coos Bay, Oregon. As far south as Los Angeles. As far east as central Nevada…an area of nearly 200,000 square miles. It was registered on seismographs all around the world, including London, Tokyo, Moscow, and Cape Town, South Africa.
First Responder: I don’t know how the hell we’re going to get him out.
Dana King: Earthquakes are one of the deadliest of all natural disasters, and one of the hardest to predict. Volcanoes typically show signs of unrest. Earthquakes strike without warning. How can scientists learn to predict the precise time, place and magnitude of an impending earthquake?
Dana King: In the hundred years since the great Northern California quake, science has made astounding progress in understanding how to answer those questions. In 1906 little was known or understood about earthquakes. In fact, scientists didn’t even know how they occurred.
Dana King: The earliest records of California earthquakes were made by Padres running the missions. The Catholic missions ran south to north in California. Their adobe brick construction often crumbled due to earthquake shaking. Upkeep and maintenance of the isolated missions depended in part on careful record keeping to ensure a reliable flow of supplies and support from the Vatican in Rome.
Mary Lou Zoback: Following on that we really didn’t have a lot of information until the time of the Gold Rush when many more people came to the area. Newspapers rose up all around and they recorded many earthquakes and kept careful account. And that was sort of what seismic record keeping was until the end of the century. In 1887 the first seismometers were actually brought to the Bay area, very early models. And they were brought here by astronomers from Lick Observatory who were concerned about how all these earth movements were affecting their astronomical observations. In the 1906 earthquake the seismometers around the Bay area went off scale except for the one at the Lick Observatory and that’s actually our first strong motion, that is strong shaking record of an earthquake. The first real records of earthquakes were actually kept by people interested in earthquakes and one of those, probably the best was Alexander McAdie, he was with the U.S. Weather Bureau, he’d been interested in earthquakes, he came to this area and started noting when they occurred and what there effects were.
Dana King: What followed the April 1906 quake was really the beginning of earthquake science in the United States.
Old Scientist #1: Each person is going to responsible for reporting on their own region, and getting this data together, so we can figure out exactly what happened here.
Bill Ellsworth: Three days after the earthquake with the City of San Francisco in ruin and damage and destruction all across northern California, the governor ordered the formation of an Earthquake Investigation Commission. To look into the scientific origins of the earthquake the destruction it caused and to come up with some answers.
Old Scientist #2: We’re going to systematically …..
Dana King: The scientists realized they had never seen anything like this before and were inspired to comprehensively study the quake. They realized they needed to gather every shred of information, every remote piece of data.
Bill Ellsworth: Many of the important things that they collected were the things that one can see just by directly walking out and looking at the fault or looking at structures that were damaged. What was the nature of movement of the fault, how much did the fault move? What are the consequences of the shaking of the ground in places of different soil types?
Dana King: More than 20 scientists contributed. They studied every seismic report from around the world. They interviewed eyewitnesses. They recorded every visible crack in the earth and every destroyed building. They even looked at eight years of tide gauge records prior to the earthquake and one year after. And they discovered and walked every inch of the San Andreas Fault from southern to northern California about 700 miles.
Bill Ellsworth: That commission was chaired by Andrew Lawson, famous geologist at U.C. Berkeley. And they produced a monumental report on the earthquake.
Dana King: The report of the California Earthquake Investigation Commission is referred to informally as the Lawson Report.
Bill Ellsworth: The report came out in 1908 and is still in use today. It’s one of the most important scientific compendiums of an earthquake and provides a rich basis for earthquake research even today.
Dana King: Modern technology has given todays scientists the opportunity to re-interpret the Lawson Report and find out more about what actually happened in 1906. Information they unearth can help forecast inevitable California quakes and help save lives when they occur.
A violent shaking…my bed was going up and down…cobblestones dancing…buildings crumbled…flat…warped metal girders.. terrific trembling…there were heaps of bricks and stone…the wall while the building seemed to split.
Dana King: There was heavy damage as far away as 60 miles from the fault. Why was damage from shaking greater farther away from the rift and what can scientists learn from that?
Mary Lou Zoback: The attention to detail in the Lawson Report of all the geological factors, features related to the earthquake was matched by the attention to detail of the effects of the earthquake, that is the shaking intensity. There are more reports of damage and shaking intensity in that report than we have for any other earthquake, even today.
Dana King: Shaking was one of the most obvious things for the scientists to analyze immediately after the earthquake. You could see it. You could easily record all of the damage.
Mary Lou Zoback: The Commission members collected all kinds of personal reports, gathered reports from newspapers and what they found was in general, as you might expect, the shaking decreased as you went with distance from the fault, but what they found locally the shaking intensity most depended on what was right underground. The shaking was lowest on hard rock and greatest on soft material and in particular the highest shaking intensities we found on Bay Fill, that is made land created by filling in the Bay. Often very poorly consolidated. Another good example of that is the town of Santa Rosa that sits well off the fault. It had actually the greatest intensity of shaking per square area of any town. And that was in part because it sits on a large basin of soft material and may actually be related to things going on on the fault.
Dana King: Research in shaking over the years has led to shake maps. Today seismographs record the shaking at more than a thousand sites in California. High performance computers and advanced instrumentation have given scientists the capability to analyze data in a whole new way. Shake maps depict where shaking will be most likely when an earthquake occurs at a specific location. They show how strong the shaking will be which is critical information for designing buildings and structures that will resist shaking.
Dana King: Real-time shake-maps are available for all of California. When an earthquake occurs shake maps are available online on the World Wide Web to help save lives.
Carol Prentice: In 1906 the San Andreas Fault ruptured to the ground surface and scientists were able to go out and map it along the entire length of the rupture. Which went from San Juan Batista almost 435 kilometers all the way up to Shelter Cove. Up until recently aerial photographs like this were the best technology that we had for making maps of the fault and you can see in this area we have a very dense redwood forest cover over the fault and its very difficult to see very clearly where the fault is. We now have a new technology called LIDAR that stands for Light Detection and Ranging. And it involves an airborne mounted laser that sends energy down and allows us to create an image of the ground surface. We actually get two images from LIDAR. We get the image of the canopy top which is shown here, very similar really to the aerial photograph but what’s great about the LIDAR is that you can create an image of the ground surface underneath the trees so that using the computer you can actually strip away this forest cover and you can see what’s actually there beneath the trees and you can see the San Andreas Fault very very clearly. Right now we are standing right there.
Carol Prentice: We can use these images to help us pinpoint likely locations of good trench sites where we can do detailed studies that allow us to determine the timing of prehistoric earthquakes that allow us to determine how fast the fault has been moving through geologic time.
Tina Niemi: Paleo-seismology is the study of earthquakes before instrumentation.
David Schwartz: Well one of the things we do to study active faults is to put trenches across them. And these trenches basically are, they’re books for reading the past. The top of the trench is the present day ground surface we look down through the trench we see different layers each layer represents a period of time and we can really read the earth’s history going back in time.
Tina Niemi: This is the longest record of earthquakes on the northern San Andreas Fault that’s ever been studied. What we have is ten earthquakes over the last 2500 years. At the time of the earthquake the ground ruptures to the ground surface and if forms like a fissure that fills in with material. The fissure then fills up with material on top of it in a flat lying way and by looking at the fissures here, here’s a big fissure and it was capped by the sediment on top of it so we’re able to date the fissure fill and the sediment on top of it to bracket the age of the earthquake.
David Schwartz: The idea is to build up an inventory of the times of past earthquakes to see if there is a pattern to see what kinds of variability there is and to use this information in helping us to forecast when the next one is going to happen.
Dana King: Recent earthquake forecasts have been based on data from trenches like these across a number of Bay area faults. How have science and engineering helped to improve emergency response since 1906 stay tuned for this incredible story.
Overlapping Voices: People all seemed to be in a daze…everything was confusion….hospital floor fell through…. hopelessly little help came….all the water mains were broken….fire house and police station …no post no telegram…the streets in the neighborhoods were fast filling with refugees.
Dana King: Another clearly visible thing scientists studied after the 1906 earthquake was the emergency response. It’s estimated that there were over 3,000 direct and indirect deaths after quake. How many more lives could have been saved by better emergency response. Well science is helping with valuable new tools like the California Integrated Seismic Network and its CISN display. Here’s how it works.
Richard Eisner: We have a very dense seismic network that has been jointly funded by California and the USGS. That provides us with data within seconds to minutes for large earthquakes in southern to northern California. We’ve partnered in developing shakemap which is this display of real ground motion so we’re not just talking about epicenter and size any longer we’re talking about what the ground is actually doing under buildings under our communities.
David Oppenheimer: The way I like to think about it is if you were standing over a puddle and you dropped a stone in it you would watch the water waves go out and those water waves go out. And those water waves are analogous to an earthquake. The earthquake generates sound waves the stone dropping into the puddle generates water waves it’s all the same phenomenon. And we have little sensors in the puddle or seismic stations on the earth watching that soundwave go past and we pick that up instantaneously with our seismometers that signal is sent here within seconds we have computers that are analyzing that signal and if they see there is an earth quake they report it we locate the earthquake, determine the location in terms of latitude and longitude the magnitude that sets off a whole chain of activities one of which is the shakemap.
Dana King: Shake maps and other details on specific quakes are delivered within minutes on CISN display. This rapid delivery is crucial for response for saving lives and for inspecting everything from roads to bridges, buildings and more.
Richard Eisner: One of the things that we’ve done in California is that we’ve provided essentially realtime views of earthquakes through CISN Display, through shake map down to the emergency managers at the local level so when an earthquake occurs they know whether they’re at the edge of a very large earthquake or in the middle of a small quake. They know how to respond. We’re all having the same picture of the ground motions within five or ten minutes after the earthquake so we know whether we have to ramp up a state response or whether we can focus on local mutual aid to deal with the damage.
Loren Turner: Knowing something about the ground shaking levels and something about the performance of our bridges and how they respond to certain ground shaking levels we can make an assessment of which bridges may have been impacted most by the earthquake. We have CISN Display running at most of the traffic management centers now and they’d be the first line response when an earthquake occurs they’d see that the earthquake occurred and they’d get epicenter and magnitude information, they’d get the shake maps as soon as those became available and they would be the ones that would put our emergency operations centers in motion.
Edward Matsuda: What we have in place right now is a process where we take shake map information and we overlay it into our analysis program. And the analysis program would do an analysis of every component in our system. And give us a map of the components that are damaged and the impact on system operations. So, within a few minutes after future earthquakes we’ll have that information available and that helps us with our emergency response and what to do with our passengers and trains in our system.
Dana King: We’re prepared to use realtime shakemaps here at our studio and with these maps news organizations can swiftly provide vital information to millions of viewers immediately after a quake. And the bottom line is that these maps allow the media to provide faster more accurate information to help save lives.
Richard Eisner: The Bay area is particularly vulnerable to the commute issue where you have people leaving there homes in the east bay commuting in to the peninsula and may not be able to get home at the end of the day if there’s an earthquake. So we want to get information out as quickly as possible to everyone.
Dana King: To best coordinate response following a quake the State Office of Emergency Services has backup power and communications systems built to withstand worst case earthquake shaking. When an earthquake ruptures an earth at the surface that’s easy to see, but to predict earthquakes, scientists need to learn what’s below the surface. What are the underlying processes of the earth?
Bill Ellsworth: The Earthquake Commission found that the San Andreas Fault shifted along this length of more than 200 miles, how is that possible? How could the earth have shifted suddenly over such a great distance. There had been no earthquake that had been seen like this before and it was a question that confounded scientists until the development of Plate Tectonics Theory in the 1960’s.
David Schwartz: Plate Tectonics is the overall model of how different parts of the earths crust are moving relative to each another. And the crust of the earth is broken up into major plates they slide past each other but over geologic time it builds up into a lot of slip that has to be accommodated.
Dana King: These great strides in understanding earthquake processes track directly back to the 1908 Lawson Report.
Bill Ellsworth: Perhaps one of the most important results that came out of this study was the development of Harry Fielding Reid’s theory of elastic rebound. He used the information developed from land surveys that allowed him to measure the changes in land surface that had been caused by the earthquake. This was something that had been understood in rough form before the earthquake but he developed the first scientific theory about how forces accumulate along faults only to be released in earthquakes. We call this the elastic rebound theory and it’s the foundation really of our modern understanding of the earthquake process.
Ross Stein: If you can think of the crust as a slab of rubber and you’re grabbing the rubber from the two sides and moving it past each other. If the fault itself were Teflon the rubber would just move by and never be distorted. But because the fault has friction then the rubber gets distorted and stresses are built up on that surface so that process is very very slow, an inch a year. And suddenly at the time of the earthquake a very small piece of that very highly fractioned surface is going to let go and as it does so it starts slipping. And in the space of a few seconds that slippage speeds up from an inch a year to 5,000 miles an hour. And that process then tears down the fault at these high speeds until it comes to a stuck patch where it can hang there for several seconds. If it’s going to be a large earthquake its going to burst through speed up again to 5,000 miles an hour and go flying into the next knot in the piece of wood if you like, hang there and then burst through again.
David Schwartz: In parts of California we just really have the San Andreas Fault, it’s the major feature. But, in places like the Bay area the fault splays its like the trunk of a tree, comes into the Bay area, big branches come out these are the major faults like the San Gregorio, and the San Andreas and the Hayward and Rodgers Creek the Calaveras the Concord-Green Valley and they accommodate most of the movement. And then even little faults come off of them and they’re like smaller twigs. Each different sized fault produces different sized earthquakes and here in the Bay area we have many faults of different sizes spread out across the entire region.
Mary Lou Zoback: Each of those faults could produce a damaging earthquake in fact taken together we think a damaging earthquake is nearly twice as likely to happen as not over the next 30 years.
Dana King: Earthquake information for the Bay area, California and worldwide can be found at quake dot usgs dot gov. Menu items link to things like Did You Feel It? Shakemaps and the earthquake information and preparedness handbook Putting Down Roots. Science now gives us all a way to clearly see and understand the earthquake risk in our own lives.
Overlapping Voices: We looked down to City Hall you could see right through it. …… Its great Grecian columns had crashed to the ground…the dome looked like a huge skeleton…the masonry had been shaken away from the steel frame….
Dana King: When the 1906 earthquake destroyed city hall no one knew how to rebuild it to resist future quakes. Even if we learn how to predict earthquakes we still can’t stop them. There will still be damage to our buildings and structures. So, how are structural engineers learning to reduce that damage and save lives?
Reinhard Ludke: The structural engineers in the Bay area are developing new techniques and new technology that they are applying in new buildings. Plus, since Northridge and Loma Prieta they’ve developed new technology and new techniques and guidelines that are being used nationally for retrofitting existing structures. This building incorporates two new techniques for steel frame buildings a dog bone joint system and an eccentrically braced framing system and both of these systems were developed and detailed so that the building can absorb and deform without failing without falling down without killing people.
Reinhard Ludke: After Loma Prieta structural engineers determined that the bridges didn’t perform properly so they came up with a technique to jacket the columns with steel casings, these ten foot diameter steel casings provide the confinement so that the column has the ductility, strength to deform and make it through a big earthquake without this freeway collapsing and people getting killed. Here we are in Berkeley, California, this is a parking structure. What the structural engineer did to retrofit this building he put the lateral system on the exterior of the building. And this is a conventional solution where they used a concentrically braced steel frame to protect this building from falling down in a big earthquake.
Dana King: In the last 20 to 30 years engineers have made buildings a lot safer. But, once structures are build to keep everyone alive the question is can engineering save the building? In our region there are hundreds of thousands of buildings at risk.
Reinhard Ludke: One new technique that engineers have developed over I’d say the last ten years, it’s called performance based engineering and because we have the capability with the technology and understanding the materials we can tune the buildings to improve the performance. So, if you have an owner that wants to have a building that not only survives an earthquake but remains functional after an earthquake we can engineer the building so that you can get back into the building right after the earthquake and continue operations, like hospitals, like police stations, like fire stations.
David Bonowitz: You shake the building from the ground and you can imagine 50 miles in any direction the whole ground shaking. And anything sitting ontop of it will also shake. Now buildings are not completely rigid, they have some flexibility so when you shake them at the bottom they sway back and forth and they kind of wiggle around a little bit and the more they deform likely the more damage you have. So, if your can prevent the shaking from coming up into the building in the first place that’s one really good way to limit your damage. That’s what isolation does.
David Bonowitz: Imagine if you could if we could somehow float the building up above its foundation and separate it like that. We can’t quite do that yet but what we can do is isolate the building a little bit by inserting between the structure above and the foundation some kind of a flexible system like rubber pads or in this case a sliding kind of Teflon like substance so that when the ground shakes the building still shakes but a lot less than it would if it weren’t isolated. So, here at the Court of Appeals there are 256 different isolators separating the structure above from the ground and its foundation.
Dana King: The 9th Circuit Court of Appeals in San Francisco is one of the growing number of buildings in the Bay area protected by base isolation including city halls in Hayward, San Leandro, Oakland and San Francisco.
Eric Elsesser: We were very pleased to work on this project. I’m a native San Franciscan, I’ve enjoyed the building from my birth and what we really saw was an opportunity to work on a national treasure one of the very special buildings in the country. It desperately needed seismic strengthening. It was damaged to some degree in the earthquake and we found out as we analyzed it it was quite substantial damage.
Eric Elsesser: This rotunda is the major theme for this building. So, this entire area was redone, refinished and it looks just like it did when it was built in 1915. I feel very safe in the building. It has a premium seismic system of base isolation which couldn’t be better in the world and I think it will do just fine in any earthquake. So, the isolators support the walls, the walls support the space frame the space frame supports the drum and the dome above and the whole building is anchored that way. When we look at base isolated buildings we are very very pleased with the outcome because we don’t see any buildings that have been isolated that have collapsed in an earthquake.
Dana King: Damping systems which are really just large pistons are another engineering approach in retrofits and new buildings that reduce earthquake shaking. Cutting edge research on building design to withstand earthquakes is taking place on what are known as shake tables.
Overlapping Voices: Hopelessly little help came. … market street was…25 feet deep…the three lower floors were completely crushed…buildings crumbled…not a soul escaped…automobiles carried out ambulance duty carrying the wounded and the dead…
Dana King: The largest outdoor shake table in North America is at U.C. San Diego where they test everything from response to shaking to the impact of a terrorist bombing.
Frieder Seible: A shake table is an earthquake simulator in which we can build real structures and then send earthquake ground motions through the table. This particular table here is the worlds first outdoor shake table there is no other facility like this in the world. We can build structures of virtually any size on the table no height restrictions, no overhead crane capacity limitations to lift big things on the table. And this way we can really test full scale structural systems. The effect of the building test which we just performed here was to show that we can design concrete high rise buildings, that they can be designed much more economically than what the current uniform building code allows us to do. Namely by using less steel and less concrete in the shear wall you can actually show that the seismic performance actually improves rather than getting worse.
Jose Restrepo: Well what we have here are the cables that will collect all of the data from the sensors, different kinds of sensors. You can see these are displacement sensors that are seeing how the wall breaths actually moves up, opens up, big cracks. These cracks here open about ¼ or an inch.
Dana King: The experiment was a great success as the building bent but didn’t break experiencing what engineers described as just cosmetic impacts from the simulated Northridge quake.
Freider Seible: What we are doing also here at the Englekirk Center at UCSD is blast simulation. So, we use the same power supply that drives this big shake table behind me also to simulate a bomb blast on full scale structural components like building columns, walls, floors, bridge columns, bridge sections and so on. We four velocity generators, these are servo controlled hydraulic actuators very similar to the ones that drive the shake table, the only real difference is that here we impart the forces in one to two milliseconds. The blast load causes shear failure at the ends of the columns then the shear failure propagates towards the column center. Now when we take these S-built columns and wrap them with these carbon fibers like you see here and then we put the same blast load on which we had put on the columns in the back you can see here that the columns they’re almost perfectly straight after the test, just the very top of the column failed a little bit.
Dana King: The work taking place at a network of shake tables at west coast universities is delivering crucial advances to prepare California and the Bay area for the next big quake.
Lloyd Cluff: The greater San Francisco Bay area, the nine Bay area counties has done an enormous amount particularly since the Loma Prieta earthquake in 1989 to become better prepared in terms of emergency response but more important than that to actually understand the hazards and then to look at all of our facilities and to tackle the most vulnerable facilities in terms of infrastructure PG&E’s facilities, the bridges, the highways and the water pipe lines and the sewers and everything and to bring those facilities up to a standard that either they can be rapidly repaired and restored or they’re hardened enough so that they won’t experience serious damage.
Stuart Nishenko: We’re here at a PG&E work site at California and 14th replacing old cast iron pipe like this here with new generation poly-pipe that is going to be threaded through the old pipe under the street. This is part of a 20 year program that PG&E has been doing since 1985 to replace about 2200 miles of old vulnerable pipe in the San Francisco Bay area. Residents of the Marina may remember us putting in rolls of pipe after the 1989 Loma Prieta Earthquake. So, now we’re doing it all over the Bay area and we’re about 80% finished with the project.
Dana King: On a personal level individuals and families can take important steps to prepare for the disruptive aftermath of a future quake.
Jeff Lusk: Although the tremendous losses from an earthquake and the enormous amount of money that is spent on retro fits those are staggering in terms of their dollar amounts people can spend a modest amount of money and take steps that will save them thousands of dollars and maybe displacement from their homes in the event of an earthquake. Strapping your gas water heater and making sure there are flexible connections so that that doesn’t move around and you don’t have gas leaks. Some other things are securing the heavy furniture in your home you can take the time to bolts in through your book cases and tie them into the studs in your wall so those don’t top over. Taking care of these non-structural items. Taking care of these things that are priceless and can’t be replaced like grandmas china and things like that. Those things need to be secured with quake wax those are loses that we can more easily prevent in a more typical moderate quake. Big heavy TV’s like we’ve got these days, flat panels and big screens those can do a lot of damage both to property and to people if those fall over on top of your during an actual event.
Dana King: Materials for securing items in homes or businesses can be purchased at most hardware stores and premade disaster kits through the American Red Cross.
Jeff Lusk: Please be ready to take care of your family and not just a kit, not a trashcan with some water and some food and some expired prescriptions in it. But, please think about everything you’re going to need to be able to stand on your own for 72 to 96 hours.
Amy Gaver: It’s no time to try to find your supplies when earth shakes, the lights are out and you don’t know where anything is. You’ll think you’ll find them, they used to be in that cabinet but ya know the thing about earthquakes is things get tossed around. So, if you wanna be able to find the things you need you have them assembled into a kit. Have the supplies you need where you need them at home, in the car in your workplace.
Jeff Lusk: And also not just to have a kit but to have a plan how are you going to contact each other when these things happen? If I’m at work in San Francisco and my wife and kids are in the east bay how will I find them when the cell phones don’t work anymore? The best thing to do is to have a phone number outside of California that you can all call and leave a message I’m fine, here’s where to find me. These are critical things basically you need to take a look at your life and say if I had no power, no water, o communications what would I do? And start to answer those questions in a common sense way.
Overlapping Voices: I never expected to to come out alive. Everyone believed their last moment had come….I’ve never seen anything like it…I want to go home mama, I want to go home repeated the little one…we haven’t any home dear…everyone believed there last moment had come..
Dana King: A major earthquake is likely to occur here soon. USGS and other scientists conclude there is a high probability of one or more earthquakes of magnitude 6.7 or greater striking the San Francisco Bay region by 2032. What would really save lives is early warning. Can we solve the ultimate mystery, how and where do earthquakes start?
Bill Ellsworth: Will it be possible to give a warning before the next big earthquake such as the one that happened 100 years ago in California. Scientifically we don’t have an answer to that question. We’ve been studying earthquakes on the earth’s surface for 100 years but we’ve been blocked from seeing inside the machine that produces earthquakes. Earthquakes occur deep in the earth under miles of rock and to understand what makes a fault what makes the machine creates earthquakes we have to go inside it. That’s what we’ve recently done along the San Andreas Fault near the small town of Parkfield located about half way between San Francisco and Los Angeles. Near Parkfield we’ve completed the San Andreas Fault Observatory at Depth. It’s the first scientific drill hole into the heart of a major plate boundary fault.
Dana King: SAFOD is part of the larger National Science Foundation effort known as the Earthscope Initiative.
Steve Hickman: This is about understanding what makes the San Andreas Fault Zone tick. Why do earthquakes start, are they predictable, what causes them to rupture to the surface and sometimes grow into really big earthquakes.
Bill Ellsworth: It’s a region in which small earthquakes occur at shallow depth so we can into them. And these small earthquakes have a remarkable property. The same earthquake occurs on the same part of the fault time and time again. We’re drilling into earthquakes that are about the size of a football field that’s the area that ruptures in these small earthquakes about magnitude 2 and they recur about every year or two. So, it gives us a wonderful scientific target a place that we can steer the drill bit along a two mile curving path to go right into the heart of the San Andreas into these zones that produce these remarkable repeating earthquakes.
Steve Hickman: This is really about understanding how earthquakes work and by gaining that understanding being able to better understand the hazard they pose to society and hopefully reduce it.
Bill Ellsworth: So, it’s going to be possible over the 20 year lifetime of the observatory to watch many earthquakes, to watch the forces as they build up and watch the process that then occurs as the fault goes from being locked to unlocking at the speed of several thousand miles per hour as an earthquake rupture runs along it.
Steve Hickman: What’s kept us from being able to predict earthquakes is a very poor understanding of what’s happening directly within fault zones where earthquakes get started. With SAFOD we have the first ever opportunity to get directly in a fault zone and see what’s happening in the hours, days or even minutes before the next earthquake occurs. By advancing our understanding of the science of what’s happening within the heart of the fault zone we can determine whether earthquake prediction is possible and how we should go about doing it.
Dana King: The SAFOD projects continuous monitoring of an active fault is a major advance in earthquake science. It’s a chance to answer that ultimate question how to predict when and where an earthquake will occur.
Stuart Nishenko: USGS and other groups have come out and said there’s a 2/3’s chance in the next 30 years of a major earthquake here in the Bay area so that’s provided a motivation for people to start improving the buildings and the infrastructure in preparation for that.
Mary Lou Zoback: Future earthquakes will be larger and closer. And, just as a comparison the 1906 earthquake was equivalent to the energy release of 30 Loma Prieta Earthquakes occurring all at the same time.
Bill Ellsworth: In the longterm the way that we’re going to be prepared for future earthquakes in California is by having structures that will resist there forces.
Dana King: Alexander McAdie wrote this in 1906 to the state earthquake investigation committee. The prime object should be to advise wisely to set forth the truth and to provide for research and investigation. And in every way work for the benefit and welfare for not only our community but all of mankind so far as the effects of earth movement are concerned.
Overlapping Voices: I was not willing to leave San Francisco then. I wanted to stay to see the new city that would rise out of the ruins. I felt that my place was there. I had something to contribute even if only in a small measure.
Dana King: In 1906 it’s estimated there were over 3,000 deaths, 225,000 homeless in San Francisco alone, 28,000 buildings destroyed. More than an 80 million dollar loss from the earthquake alone and another 320 million dollar loss from the fire which devastated the downtown behind me. What will happen when the next earthquake occurs?
Bill Ellsworth: If we can succeed at understanding the ultimate forces that earthquakes can deliver to the earths surface we’ll be able to give very clear guidance to engineers and architects so that they can build structures to resist future earthquakes. To ensure that our critical facilities such as dams and bridges will not be subject to failure in whatever earthquake may someday hit us.
Lloyd Cluff: Within the Bay area there’s probably over 100 distinguished earthquake scientists and engineers and many of those including myself live in the proximity of active faults.
Ross Stein: We recognize that we reap the riches of a landscape built through repeated earthquakes this is why we have the San Francisco Bay as a result of these faults. It’s why we have the wine country it’s why we have the beautiful climate. If we’re going to benefit from it then we also have to prepare for the occasional bad things that these faults fire off at us. And most people and most of the laws and most of the desire on the part of the population is to build to survive earthquakes and to live safely among them.
Dana King: Quakes are going to happen in California. An earthquake can hit at any time and it will surely be destructive. But, with the amazing advances in engineering and science and the commitment of the community to prepare and be ready surely it will be less destructive and lives will be saved.
Title: Shock Waves: 100 Years After the 1906 Earthquake
Shock Waves is an Emmy Award nominated USGS television program that aired on San Francisco's CBS-5 in April, 2006 during the week of the 100 year anniversary of the Great San Francisco Earthquake. The program is hosted by Dana King and was produced and directed by Stephen M. Wessells. It traces the century of scientific and engineering progress since the great quake. Historical recreations, hundred-year-old film footage, and stunning still photographs convey the extent of the destruction and the human and scientific response to the catastrophe. The program features 3D animations, cutting edge research and expert interviews with some of the world's premiere seismologists and engineers. The Bay area is presented as a showcase for earthquake preparedness. Note: Engineering animations are owned by SEONC and Forell/Elsesser Engineers and U.C San Diego. Japanese quake video from convenience store security cameras and TV studio security cameras is owned by NHK, Japan. Classroom earthquake happening shot is owned by the University of California. 1989 Loma Prieta Earthquake video shots are owned by KPIX CBS-5, San Francisco. Any use of these materials requires written permission from the respective owners of this material listed here.
Date Taken: 4/18/2006
Video Producer: Stephen M. Wessells , U.S. Geological Survey
Note: This video has been released into the public domain by the U.S. Geological Survey for use in its entirety. Some videos may contain pieces of copyrighted material. If you wish to use a portion of the video for any purpose, other than for resharing/reposting the video in its entirety, please contact the Video Producer/Videographer listed with this video. Please refer to the USGS Copyright section for how to credit this video.
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