9UNP0170SD_Harold_Tobin_WordPress

- Welcome, everybody, to Wednesday Nite at the Lab. My name's Tom Zinnen. I work here at the Biotechnology Center at the UW-Madison. I also work for the UW-Extension Cooperative Extension. And on behalf of the Wisconsin Alumni Association, thanks for coming to Wednesday Nite at the Lab, which we offer every Wednesday night, 50 times a year, here at the Biotech Center. Tonight, we get to have Harold Tobin talk about his work in drilling deep into the sea beds to figure out earthquake faults. Harold Tobin is an associate professor of geophysics at UW-Madison. He spends his time studying the faults at the earth's tectonic plate boundaries, especially those that lie beneath the sea and cause devastating tsunamis. His research spans seismic wave imaging of the earth's crust, month's-long expeditions at sea, sampling below the sea bed and laboratory experiments in the physics of faulting. 

Professor Tobin is the Chief Project Scientist for the Nankai Trough Seismogenic Zone Experiment, a long-term effort to drill into and monitor undersea earthquake faults off the Pacific Coast of Japan. He operates the Geology and Geophysics Departments Geoscience Visualization Lab in Weeks Hall and teaches courses in oceanography, geophysics and plate tectonics. Please join me in welcoming Professor Tobin to Wednesday Nite at the lab. 
(applause)
 
- Well, thanks very much Tom. I take it you can hear me. I'm pretty loud. I have the microphone, but let me know if you have any trouble. I really appreciate the invitation to speak to you. 

This is Wednesday Nite at the Lab. I do operate some lab equipment here in the department, but the lab I'm going to talk about is really that one there. And it's kind of a unique laboratory in the world. I'll try to tell you a little bit about the background of why we spend time going to see, to look at earthquakes, and the faults that generate earthquakes, and the processes that go on in those faults, and a little bit about what life is like for doing this. Tom's introduction was really thorough and told you a little bit already about what the project is. This past September through November, I was on board that ship right there, which I'll tell you a little bit more about in a minute. For eight weeks, that's true, month's long expeditions, along with scientists from many different countries around the world. And we started the first phase of this project that's actually going to last for about the next five or six years, depending on budget, schedules, weather, typhoons, many other things, to try to complete a very large scale, one of the largest scale projects in the earth sciences that's really ever been undertaken. So let's take a look. First of all, I guess the question is why go to sea to look at this? 

When you think of a geologist, you probably think of somebody with a rock hammer traipsing around the mountains, or something like that. But as we all saw very clearly in 2004, the most devastating earthquakes on the planet, in fact, the largest earthquakes that release the most energy, virtually all happen on faults that are actually lie beneath the ocean. And, in fact, from the point of view of plate tectonics most of the key areas, the boundaries between the different plates lie beneath the sea, often lie beneath the really deep sea. So as geologists, we need to go to the ocean, of course the ocean is 70% of the surface of the earth, so I guess it's not too surprising. You might think of oceanographers as the people who go to sea. We're not really oceanographers, we're marine geologists and marine geophysicists who are looking at processes that happen below the sea bed. So what we're interested in are some of these really fundamental questions about how earthquake faults work. And in a sense this is the dirty little secret, or maybe it's not such a secret, of geophysics today, is despite 100 years of seismology, despite all the work that's gone into looking at faults on land, and looking at the waves they produce, the damage they produce, we don't have a really very good fundamental theory of how earthquakes work. And by that, I mean we know the basic principles, that earthquakes are because stresses build up in the earth's crust, and two pieces of the earth's crust are in contact with each other. It's frictional contact. 

They're rough surfaces and they tend to stick together. And when the plate forces overcome that friction, they pop and slip, and that might take 100, or 200, or 300 years to build up the stresses involved. But that earthquake slip is fundamentally frictional. That's all well and good, but the question is we know a little bit about how the plates move. And we know a lot about the basic physics of faulting. But we don't understand what it is that controls the specific time, and place, and occurrence, and especially size of earthquakes, and also the tsunami that they spawn. So what we're interested in is a particular part of the plate tectonic system that I'll talk about, and how do these faults really work. How do we get inside the faults, make measurements that we've never been able to make before, because earthquakes happen miles deep into the earth, right? They don't happen up here on the surface, where we can easily dissect them or look at them closely. But how do they work before, during, and after large earthquakes? 

That event that happened in Sumatra, I think everybody knows so much more about tsunami than they did before 2004. The term wasn't even that familiar to a lot of the public at that time. I like this quote from somebody far outside the sciences. And, of course, this was a figure about the largest natural disasters in terms of loss of life at the time that that event happened. I took it from the Washington Post. It's the largest death tolls from various kinds of events over time. And we know now that that earthquake in 2004 had a death toll of something like 250,000 people, which puts it up there in the top three of four of all time. Many of which, of course, are earthquakes. And as we know, the devastation from that earthquake was not so much the earthquake, but the tsunami that was generated by it and inundated the land in many places. Okay, well similar to Sumatra, there are other places around the world. 

And this project's been in the forming stages, for many years, actually before 2004. Your first question might be to me, why aren't you guys working off the coast of Indonesia? And the simple answer to that is that we actually knew relatively little about that piece of the earth's crust before that earthquake. It wasn't all that studied. And for the purposes of the kind of very pinpointed project that I'm going to talk about, we needed to go to a place where we have a lot of pre-existing, sort of geophysical information, geological studies, and things that make it amenable to the kind of study I'm going to tell you about. So the area that we're working in is here off the coast of Japan. And it's a little bit dark up there. But this region, off the south western cost of Japan, off this island just south of Kyoto and Osaka, is a region with a deep sea trench called the Nankai Trough, in Japan. Here it is in perspective, in the bathymetric perspective of the sea floor. So there's the coastline. 

And it's a region that has had frequent, great earthquakes in historic time. The term great earthquake to a seismologist means any earthquake with a magnitude, Richter magnitude, of 8 or above. And the key things, as you probably remember, the one that happened in Sumatra was greater than magnitude 9. It's a logarithmic scale. It was actually even 100 times larger than the San Francisco earthquake in 1906, in terms of energy released. This region has had repeated earthquakes of magnitude 8, or so, for a historic record of 1,500 years. It's the place we know the most about the long-term earthquake record, mainly because in Japan there's a very good historical record, in general. So each one of those earthquakes over that 1,500 years has caused a tsunami that were actually relatively large tsunami for the size of the earthquakes. And they reach the shoreline. They were recorded because of the damage that they did at the time to villages and towns along the shore. 

The last two of those earthquakes happened in 1944 and 1946, sort of side by side during the war, actually, in 1944. And it was recorded by a number of seismic instruments, even at that time in Japan and around the world. And it sort of covered an area, the earthquake slip covered this really large area of the earth's crust. This was an enormous earthquake. It moved sea floor by many meters. And it caused a tsunami that was something like 11 meters, nearly 40 feet high at the coastline when it reached the coast. And many thousands of people were killed at the time. Two years later, another event happened. What we're basically doing is saying let's take this area that had an earthquake in the past, had many earthquakes in the past. And we know that the interval of recurrence of those earthquakes is about 90 years, or so. 

And let's go there and study that fault that had a relatively recent slip. To a geologist, 60 years ago is relatively recent. And is building up its stresses towards a future one. So that's the fundamental, sort of setting for where we're trying to work. And a part of the motivation is illustrated here on this slide, which is the Japanese government sort of seismologist best estimate of the likelihood of major earthquakes in Japan in the future. That same region I just showed you is here. And it's among the highest risk that they identify in Japan. So the way earthquake forecasting goes, notice I didn't say earthquake prediction, that's a little bit of a different game. But earthquake forecasting is that the risk of a certain magnitude earthquake with a potential for a lot of devastation on the coast is as much as 90% over the next 50 years; 60% to 70% in the next 30 years or so. So there's a lot of motivation to put a lot of effort into studying this area. 

From within Japan, just the point of view the hazard. Why do people like me care about it? This turns out to us as fundamentally the best place where we can go and bring all the different geophysical and geologic tools we have to bear to study one of these faults. And I'll try to take you through that a little bit. And the key for me is the ability to use this phenomenal drilling ship. Basically the technology that's developed for oil and gas type of exploration. We're taking that same technology, but directing it toward fundamental research in earth sciences and hazard assessment from these kinds of earthquake faults. And there's a program I want to tell you about, maybe some of you have heard about the deep sea drilling project, or even Project Mole Hole, which goes back to the early 1960s. The Mole Hole was before I was born. But the current sort of phase of that international program in scientific drilling is this thing called the Integrated Ocean Drilling Program. 

And it's a collaboration of the U.S., Japan, a number of different European countries, and several other countries, 20 in all, to look at the planet beneath the oceans. And there are multiple oceanographic vessels that have been used for this process. This is the American ship that's done 20 years of phenomenal service and drilling into the sea. This is an ice breaker ship that collected core samples from up in the Arctic Ocean a few years ago that was a tremendous success at looking at the climate history in the Arctic. And the latest and sort of greatest oceanographic vessel is this new ship which is known in Japanese for "Planet Earth." It was built by the Japanese government as sort of their component of this international program. It's sort of a phenomenal ship in every way. The derrick on that ship stands 120 meters above the water level. If that doesn't mean much to you, that's a little taller than the Statue of Liberty. I'm trying to think of a way to talk about it. 

I recently calculated that if you dropped it somehow into Lake Monona, the top of the derrick would stand above the statue on the top of the Capitol Dome. So, including the hill, including the capitol and everything else, just from the waterline to the top of the helicopter landing deck there is about 80 feet or so. So it's a first-class laboratory. It's got a four-story lab that's in this part of the ship. We have, usually 26 scientists on board at a time potentially, to work on all of these laboratories that I'll show you a little bit about in a minute. It can drill holes and place instruments down into those holes to measure things about these faults below the surface, and take core samples. And we can do all sorts of things on the core samples. It's actually one of the most advanced sort of geological analysis labs in the world. It can also maintain one position in the sea for a very long time. If you're going to drill a hole in the sea bottom, you need to be able to stay in the same place, right? 

So the ship has six thrusters, six propellers, essentially, that stick down out of the hull. They can be rotated any direction you want, and then power delivered to them different ways. Then, they can be controlled by GPS and this thing called a dynamic positioning system. During the eight weeks we're at sea, well, we weren't always in the same place, but it always maintained station to better than six feet. Okay? It's 670 feet long, and it never moved unintentionally more than six feet off of its station. So that's a prerequisite for being able to drill. And that's including in storms, strong sea currents and other things. Okay, well, before I tell you about the project itself, I want to give you a little bit of background. And some of this is sort of Geology 101 stuff. 

Bear with me if this is extremely familiar. But maybe it's not completely. The fundamental thing about earthquakes on the planet, in fact, part of the fundamental way that we discovered that the earth's crust is made up of a series of tectonic plates, is the fact that earthquakes don't just happen anywhere, they happen in very specific places, right? This is a map of the whole earth, with very small dots that you can't really see, but maybe you can see the colors. That is a plot of all the earthquakes above magnitude four that happened anywhere on earth over a ten-year period. Okay? So you can see that there's lots of places where there's no dots, right? The interior of the continents in general don't have many earthquakes, especially a large size. But the places like the mid-Atlantic ridge, where the plates are separating and sea floor spreading is going on, are picked up by earthquakes. But even more so, the deep sea trenches, like all of these trenches surrounding the Pacific, are picked out by earthquakes, and in fact, the largest earthquakes. 

90% of all the seismic energy that gets released on the planet happens specifically in these deep sea trench locations. And we call those subduction zones, because they're places where one of the earth's plates with subducting beneath the other. If we look at that-- Yeah? 
(inaudible)
 
- Sorry? 
(inaudible)
 
- Oh, that's a tough question. 
(laughter)

 I have never counted them. I think that if I said the number 10,000 I wouldn't be off by, in order of magnitude anyway, so something like that. Yeah. So if we look at one of these subduction zones, you know, off the coast of South America, off of Indonesia, off of Japan. The Aleutians in Alaska. Then in a relatively near surface, let's say the upper 100 kilometers, or so, of the earth the structure looks something like this. We have one plate that's passing down beneath the other, as it is subducted or carried down, back into the earth's mantle. And the edge of the land lies over it, the continent will be on one side, the oceanic plate typically will be on the other side. The type of crust on those plates is a little bit different. It makes the oceanic plate denser and it gets carried down below as they converge on each other. 

The rate of that convergence is on the order of a few centimeters a year. And if you want to put that in terms you can understand, your fingernails grow about as fast as the plates in the Atlantic are spreading apart. So if you let your fingernails go for an entire year that's one year of plate motion in North America. Not real fast, but detectable and certainly measurable. And it turns out devastating, because the one part of subduction you've probably heard about before is that when the plate gets deep enough, about 100 kilometers, melting begins off the top of it, and that fuels the volcano, something like the Cascades in Oregon, let's say, or the volcanoes in Japan or Indonesia. But much shallower than that, the two plates are in contact. And that frictional contact with each other, that is where the earthquakes are generated. Down here, it's too hot and too high pressure. The rocks actually deform like toothpaste, or like cold molasses. You know, they are very viscous. 

But they flow, they don't break. Shallowly in the upper 30 or 40 kilometers, they stick together and they rupture in earthquakes. And when an earthquake happens, it happens on that boundary between the two plates. And then it typically starts at a depth relatively deep, like 30 kilometers, or so. But the slip on that fault, once it gets going, ruptures up towards the sea bed, and also ruptures along the fault. In Sumatra what we saw was that the size of that earthquake was because it not only broke one place and moved up to the sea floor, but then that sort of unzippered a 1,000 kilometer long block of the earth's crust. The scale of that event was massive. There was an average slip on the fault in just a minute or two of 21 meters. Okay, 70 feet. The two pieces of the earth's crust slipped. 

That represented an accumulated time of about 200 years of plate tectonic motion. The plate's moving relatively fast. So when that happens, well, it sends out seismic waves that radiate out and of course, shake people on land. But it also displaces the bottom of the ocean. And when it displaces the bottom of the ocean, that's the potential for creating a tsunami. So in a very simple sort of way if we think about what's going on in a tsunami, it looks something like this. If we start up here, and say here's our plate going down. They're stuck together, but at the big scale the plates are still trying to move. So they keep moving in the far distant. There's a little bit of deformation. 

It's elastic deformation, meaning like big sort of rubber foam blocks that kind of distort. What happens is, this overriding plate gets pulled down and back, and that actually causes it to pop up in some areas, but get pulled down, centimeter by centimeter, year by year by year. Eventually, that causes so much stress on this boundary that when it breaks and ruptures in the earthquake, it uplifts the sea bed. But what that does, of course, is uplifts the water above it. Now that drawing is obviously very exaggerated. But over an area a few hundred kilometers wide, you get a meter or you get two meters of uplift of the water. That's enough to start that wave, propagating away from that zone. And that's what causes the tsunami damage. Of course, it might be two meters high out in the open ocean. Like any wave when it gets close to the shore, it slows down and builds up like a breaking wave. 

And because they start in such deep water, they build up to such very large sizes. Okay, so were interested in this process of how are these plates stuck together and what happens when they come unglued. Right? So that's the fundamental goal of this project, is to actually try to access those faults for the very first time. Again, the earthquakes happen deep in the subsurface. We have seismometers on the ground. They can make measurements, but they're all essentially in the far field to a scientist, meaning they're far away from where the action actually is. Something's going on inside those faults. We want to know what those processes are. We've never had a way to put instruments inside the faults, or even take samples from the faults directly. 

Now we can look at faults as geologists on land, but anything that's exposed at the surface of the land by definition is sort of an old, dead fault, or else it's along something like the San Andreas. It's just kind of the dirt on top. And the real earthquake slip is happening much, much deeper. This particular place in the world affords us an opportunity to access the upper end of these faults and the earthquake slip might start down deep and come up, so this is another cross section. The land is over here. The open sea is over there. That's Japan now let's say. And this is the deep sea trench. And we know that the fault slip comes up the fault, comes up towards the surface and then eventually dies out into a region where it's not really rock anymore. It's just sediment in the sea floor. 

And it's sort of soft and squishy, and can't actually release energy as an earthquake. And so what we're fundamentally interested in, is a transect of sites where we can first of all, make images of what's in the subsurface. I'll tell you about that in a second. And then poke some holes into that at different places along these faults like, for example, those three spots at different depths, and look at how the faults are evolving with depth, meaning changing as we go down the earthquake fault, from the place where it's not really a seismic fault to the place where it is a seismic fault. That's the fundamental difference between looking up here or out here, and then looking down in this red zone, which we term the seismogenic zone. So that's the fundamental goal. Sample the fault zones and make measurements. Another way of looking at it from underneath maybe, is here's the plate going down. Here's the area that's locked to produce the earthquake sometime in the future and slowly accumulating stress and strain. And we want to get our observations in long before the earthquake happens, and also look at the products of the last earthquake there. 

And then what's going to happen as we build up over the next couple of decades, literally, towards the next one. So some key objectives then. How do the subduction faults store up the strain of plate movement and ultimately break in massive earthquakes? Those are the kinds of questions we want to ask. What's the nature of the shallow part of the fault zone key to the tsunamis? I didn't quite say it. It turns out that the size of the tsunami, relative to the size of the earthquake, is mostly a product of how much of that slip gets all the way near the surface of the earth. If it all dies out down by ten kilometers down, it won't make much of a tsunami. And we know, in fact, there's good example there's an earthquake three months later after the one in December, 2004, that was quite large magnitude, 8.7, it generated very little tsunami. So there's distinctions among earthquakes and the tsunami they generate. 

We'd like to know which places are especially hazardous. And where is it stuck versus freely slipping between these large earthquakes. Very importantly, if we can put instruments in the fault through this long-term monitoring, can we detect some kind of precursory signal. Is there any advance warning the faults give us. Everybody wants to know about earthquake prediction right? Can we predict earthquakes and give people a warning? The people in Reno, Nevada, right now, I don't know if you've been reading the newspapers, are worried because there's been a swarm of earthquakes up to a magnitude of 4.7 that happened a couple of days ago. There have been something like 500 felt earthquakes in Reno, Nevada, in the past week. And nobody really knows, though, if that's building up to a big earthquake or if it's just a whole bunch of small events that are now going to die back down. That's part of that dirty little secret, that we don't really understand the earthquake process very well. 

May be it's because we have never put our instruments right into the faults. By the way, the answer to the question is no, we can't predict earthquakes. The fundamental goal of a project like this, people ask me all the time, are you going to be able to predict earthquakes once your instruments are there? And my answer is we don't know. What we're looking for is actually, is there a signal that we might be able to develop an earthquake prediction method in the future, or are we going to demonstrate that, for various reasons having to do with sort of critical state physics, that they literally don't give you any warning, perhaps until the first seconds of the event actually happening. We don't know the answer to that. And we're going to look at some key questions, too, that have to do with what's going on in the rocks, what's the state of stress, and maybe I'll tell you just a little bit later on about pore fluid pressure. It turns out that faults can be lubricated by the water that lies in the cracks in the rocks. And just like your car tires hydroplaning, or an air hockey puck on a table, if that water has high pore fluid pressure in it, high pressure in the water, it can actually jack the fault apart and make slip easier, or more difficult if it's drained away. So that may be a key control on earthquake faults. 

Okay, well the first step that I mentioned was that when we needed to carry out this imaging of what's below the sea floor. So just like anybody else, like a doctor trying to do surgery, we need to know where we're going. If we're going to put a pin prick in this drill hole, we'd like to know what we're drilling in to. So this first step is again, to use the technology that's most advanced in the oil and gas industry. But we're applying something different. And this is something called a 3-D seismic reflection survey. The word seismic is up there now, confusingly, not because it's about earthquakes. But it's because we're basically running the world's biggest echo sounder system. You make a boom in the water, much stronger than the echo sounder does, and record it on, in this particular case, about 6,000 microphones. And they're all being towed behind the ship. 

You can see the front ends of these streamers. And they extend three miles back from the ship, four of them. And there's also some other things that the ship is towing along. And it basically sort of mows the lawn back and forth over the area that we want an image, and generates an image of what's below the sea floor. In a sort of schematic way, here's how it works. There's a little kind of cartoon-like video here. The ship sends out its bangs. And it sends back, not only an echo from the sea bed, but also ones from all the subsurface layers. Now those make images that we can use to interpret what's below the sea floor, geologically, hopefully. So what's drawn on there would be an interpretation of those sound images. 

By acquiring that survey in 2006, by the way that also is a sort of a separate international group, U.S. and Japan partnered. It was $11 million to collect the seismic survey. I'm one of the PIs on that. But there's about six or seven others. And we imaged in an actually unprecedented detail for us. This is the kind of stuff that's old hat to folks who say, drill in the deep Gulf of Mexico for Exxon, or somebody like that. But for scientists to have seismic reflection data of this quality is really unique, and we were very fortunate. Here's an image, the sea floor is actually on top there, so you kind of see some of the surface. It's hard to get your bearings on this, but that's about 50 or 60 kilometers in length. It's already two kilometers down in the water, 2,000 meters water depth, and then down to 8 kilometers below sea level over there. 

And it's about 10 kilometers wide, or so. And maybe you can see some of the geological layering. We'd have to zoom way in to really see in detail. But we pick out our images of these fault zones. And my slide is labeled with a lot of jargon. But fundamentally, the boundary between the two plates is this set of sort of a bright reddish spots that are down in here. And those are our targets for drilling, these faults, and how they come up to the surface and have produced tsunamis. And some of the evidence of tsunamis in the past are actually these sea bed slumps and landslides from when the fault has slipped in the past. So that gives us some targets. That's just another image, actually, of how we strip away seismic reflection data and come up with these three dimensional images of what those faults look like. 

And that's kind of what's picked out here, and then site our drill holes. The key thing about having this very rich imagery again, is that we can only make a hole this big literally into a fault zone. So how do we learn about something that's 1,000 kilometers long and 200 kilometers wide from a hole this big? Well the answer is partly that we have a lot of chutzpah to even say we can. But the other answer is that we have all of this, sort of imaging that's much like a cat scan, or something. And we have some points that are the ground truth and we can extrapolate away using that. Okay, so our first phase of drilling began out here. Now this is another cross section. Sorry for flipping things around. The trench is over here and the land is over that way. 

On this slide, it's the other way around. The land is actually up over here somewhere. But this is the trench. Those are my faults again, just like in the cartoon I showed before. What we did in this first phase of drilling was just pile it in the first holes. We only drilled the parts that are shown in sort of solid colors here. But even those holes are anywhere from a few hundred meters into these faults, to as much as, this is about a mile deep, just that part right there. And it's already in water that's 2,000 meters deep. That's the pilot for our ultimate goal, which is to drill a 6-kilometer deep hole that crosses the faults and gets into the earthquake-generating part of this fault zone. That's coming over the course of the next few years we hope. 

But we got some initial results from going out and doing this first set of drilling, basically to document what the faults look like in the shallow part, so we can compare them to what they look like when they get down deep. Well, we have a lot of technology to bring to bear on all of this. And I'll show you a little video clip in just a second. For example, on board the ship, here is a remote operated submarine, ROV, that's a robot sub controlled on a tether. They can send signals down to it and get video back. And also, it has manipulator arms on it, so it can actually do things. That's a picture from its video camera of a drill bit near the sea floor. And, actually I'll show you a video of that, so I'll leave it. You notice I stole my slide from some of my Japanese colleagues here. I can't read that either. 

But you know, the sea floor environment is pretty harsh. And it's a difficult place to work. And you can't go down there. In fact, if you do go down there you're in trouble. I brought these along. A different project. Years ago, I did some diving work with Alvin, the submarine that's used for deep sea diving for research purposes. And like all the other Alvin divers, I wanted a souvenir. So if you take a Styrofoam coffee cup and you strap it in a mesh bag on the outside of the submarine, go down 2 kilometers to the bottom of the ocean and come back up, it comes back like that. And we all decorated them with the date of our dive and our names. 

I'll pass it around, as long as you don't smush it, and as long as I really, really want to get it back at the end. But there's my espresso cup that started out as a grande, I guess. Life at sea is intense. You're spending a lot of money just to be there. I probably shouldn't even tell you how much it costs of your government's dollars, and Japan's government dollars, and everybody else to keep us all on board. But I will, I guess. You know, that the operating cost of this ship is something like $200,000 a day. So certainly you work 24 hours a day. You work fast. You try hard to get everything done. 

There were about 150 people on board to make this happen. Only 25 of them were scientists. They're cutting the core that came up in one of the particular coring operations. Geologists working on board to analyze those cores. These are some of the core samples that come out of that drilling operation. I brought another prop, which is a sample. I won't open it up. It's actually an older one. We treat our newest ones with more care. I don't carry them around. 

This is one from a previous operation that I never did any lab work on. But that's the size of the core. So like I said, we really have just a pin prick into these fault zones. That's with a plastic tube with some sealing and all. Inside is basically some very dull to the naked eye, you know, shaley rocks. Okay? These may not be very exciting looking. I don't know if I'll pass that around, because there's not so much to see. But people work very hard on these core samples and analyzing the faults that they see in the cores. Many different analysis happen on board the ship. 

Chemistry is going on. Various kinds of measurements of rock properties. Properties maybe you've heard about of paleomagnetism. What's the magnetic signature that's in the rocks. That's a cryogenic magnetometer that is on board. And it's cooled with liquid helium, down to very cold temperatures, so they can do magnetic analysis of rocks. And may be one of most exciting tools we have on this ship is there is actually a medical X-ray CT scanner, so that all of those cores besides being split can be imaged in a pretty high resolution 3-D imagery. That's a photograph of one of the cores split in half, okay? And you can see some geologic features in it. But that's a CT scan of a similar piece of core, may be the same one. 

No I think it's not the same one. But at sort of a similar kind of scale. But we get some just beautiful images out of these CTs. This is, oh, that's not the slide that I thought it was going to be. Oh, I see, okay. I'll actually just jump ahead and show you the CT scan. Right here. We get some phenomenal images. So here's a core. Here's a cross section. 

I'm going to show you a movie of some slices through that core. And here we go, slicing through the core sample. We're down at sub millimeter resolution. This is actually a piece of that fault zone. It turns out these gigantic earthquakes happen on faults that are very, very thin. And that's something that we hypothesized. We've confirmed with this piece of drilling is that the actual fault slip surfaces, and there is highlighted in a kind of cut-away, actually a 3-D model view. I think it looks kind of cosmological. But actually that's a few millimeters thick, high density zone. That's the sheer surface that fault slip actually happened on in a particular place. 

So having these CT images is almost better than having the split cores. You can only see one face if you cut a core open, but we get a full 3-D view. Yeah? 
(inaudible)
 
- And then you see this one millimeter of fault. 
- In a sense, yeah, that's not the only fault in those cores. And it turns out that what we image as a seismic reflection is often say a band, 10 or 20 meters thick with many individual surfaces, like the one in that video. And they're sort of braided, think of a braided stream in cross section. You know, it's many different surfaces that probably represent different earthquake individual slips. 

And then you see them all amalgamated into a rock core. And the job of a geologist is to tease out that history over, say 10,000 years worth of earthquakes, or something like that. You know, just perspective on plate tectonics and faulting. Think of a mountain range like the Himalayas 8,000 meters high, right. At the top of Mount Everest, highest point of land on earth. You know what's up there geologically? It's Marine rocks. It's deep sea sediments, okay? So they started at the bottom of the ocean, in between India and Asia. The two continents collided. 

Mount Everest rose to that point. How does it get to 8,000 meters above sea level? It happens by tens of thousands of individual earthquakes, every single one moving the rocks up a few more meters. Over time, erosion happening off the top. And so somebody said once that earthquakes are the quanta of plate tectonics, meaning they are the single units of tectonic activity. All right, I think I'll skip, because I have a tendency to drone on. And I'll go on too far. More evidence from some of the results from the core. I can discuss some of the core actual results that we got so far in a little bit more detail for people who want to know it. One of the things we identified in cores are actually deposits that are evidence for these past undersea landslides that I mentioned before. 

So they support this idea that the faults here in this particular subduction zone have broken all the way to the surface and have produced, that's it's a place where it's characteristic for it to have these very large tsunami. Because we have the core samples, we can have a record going back much deeper in geologic time of earthquakes happening one after another. It takes a lot of precise dating, then, to see if those happen clustered in time or some other way. But that's one of the kinds of things we're trying to investigate. Okay, so the core samples mostly give us a geologic record. But we do some other kinds of measurements, as I said, trying to get measurements of the properties of the rock. And one of the things that we do is another technology that comes from the oil and gas world, but we're putting to good use called logging oil drilling. Okay, geophysical logging is just a buzz word that means making some kind of measurement down in a bore hole. It could be a measurement of the electrical conductivity of the rocks, or the speed of sound waves through the rocks, or their porosity, which we measure through neutron back scattered methods. All kinds of instruments can go down the bore hole and actually measure things about the rocks, even if you don't have core samples. 

And if you do have core samples, there's still measurements we can do in the holes that we can't get any other way. So when we do this logging while drilling, we actually have special drill pipe that has these sensors embedded in the drill pipe. And we build that into the drill string and send it down and drill a hole in the sea floor. The key advantage to that is just as we're opening the hole, so we get the real properties of the rocks down there. And we can actually get the measurements back on board in realtime so she's looking at some of the logging data on the ship in the comfort of the lab while, 3,000 meters below her feet under the ocean, the measurements are being taken. And actually interestingly, are being sent back up. How do you get a signal from a vibrating, turning, rotating drill bit back up to the surface? You can't run a wire down there, it turns out. So they use a thing called a mud pulser. Well, the mud pulser is like a modem that runs on little pressure waves in a column of water or mud. 

So inside this thousands of meters long drill pipe is a column. It's actually mud because we use it as a lubricating fluid. They add some clay to the water that goes down the drill pipe. So they pulse little pressure pulses at the bottom. It comes up as a little acoustic wave up through that mud, and is decoded at the rig floor on the ship. And you can get your actual log measurements out at high resolution that way. It's like if you had a telephone modem in your house for your computer. Or I'm sorry, instead of a telephone modem, you know, you used your sewer pipe, right, as the modem or something. Yeah? 
(inaudible)

 
- How much data comes up? 
(inaudible)
 
- No megabytes! The mud modem works at 8 bits per second. One byte. Okay? That's doesn't sound-- Not kilobytes. Not megabytes. 

One byte per second. That's actually enough to learn a lot, because most of those measurements are just a number. They're a value. So an 8 bit word, for the people in the room, can send you a pretty large range of numbers, right? So you just have to send that up. You know your depth from other information, so just what's the electrical conductivity right here at this depth. You send a number up. So it turns out we can send a whole bunch of different signals, and repeat them every one minute or so. So we get about a less than one foot, you know, a few tens of centimeters resolution on those measurements. Of course, the tools also have memory. 

And they record a lot higher resolution signal. But we get the realtime data at that kind of resolution. It's the technology that blows me away. I don't know. Okay. So whoops, I'm going the wrong direction. What's going on? There we go. This could get technical. And I won't unless people want to ask me about it too much. 

But one of the things that we do, this is with the memory data, actually, not the realtime data, is we can not only measure a value of the conductivity or resistivity, but we can actually measure it at different points around the circumference of the bore hole, because the tool is sweeping around. It's rotating as the drill bit goes, okay? And so when we measure that, we build up a map of the bore hole walls. So this cigar-shaped thing is the actually sort of an image of the interior of the hole we just made. And that image, it turns out, has dark spots and light spots, which actually correspond to areas where the hole is sort of intact and areas where rock has fractured off the sides and come in. And so it turns out that that is a way for us to determine the direction of those tectonic stresses. It's perpendicular to where those fractures happen. So this image over here is actually like if we sliced that cigar and then unwrapped it and flattened it, okay? And then that's vertical distance, hundreds of meters down this way, so it's very squashed. And it's north on this side. 

South in the middle. North again on that side. So it's just an unwrapped view of that hole. And it turns out that these black bands that look like tire tracks running down there are these very consistent orientations of the tectonic stress in the earth's crust at that location. Well, it's hard to explain this without a pretty long science talk. But basically when we measured those stresses at all these different bore holes we drilled, we found that this region all out here, is in one state of stress. And this region back in here is in a very different state of stress. Those measurements were all at 90 degrees to all the other measurements. The separation is just a couple of thousand meters across there. And what that actually tells us is that something we hypothesized up front looks to be confirmed. 

The fault is locked and building up stress towards an earthquake in this region. And is not for all of this shallower region out in here. So that was an exciting result for us. Let's see, I do want to actually show you a little bit more video. Well, actually, I'll wait till the end, because I don't want to run out of time to say a couple more things. I've talked about the cores. I've talked about down home measurements, those logging tools which we ran. And now I'll talk about one of the things that still in the future plan, we haven't started doing it yet. But that is basically, as I've said, we want to do long-term monitoring of these fault zones. So a technology has been developed through this ocean drilling program to basically do something that's sort of like making a well. 

We install steel pipe that instead of coming out when you stop drilling the hole, you leave in place, and then put a seal on top and hang instruments down in that bore hole, so we can measure various things we want to know. Like put seismometers down in the bore hole, or put pressure sensors, or strain gauges that are basically ways to measure the stresses in the rock. The things are called CORKs. It's a great acronym. I think it was one of these cases where the word came and the acronym came about five years later. Circulation Obviation Retrofit Kits. I think it was actually, the acronym became a joke quickly, or was a joke to start with. But the idea is that you need to seal the bore hole in order to measure things like the pore pressure in those faults. We can't have the hole itself be a conduit out. So our goal is to install these instruments into the subsurface. 

That's a considerable bit of technology that's not going to be an easy thing to do. But our ultimate goal for this whole drilling program is to get that 6-kilometer deep hole in there. This is just another depiction of our seismic reflection image. Drill all the way down across the whole plate boundary into the hard rock of the oceanic plate that's going down. That will take about 6 kilometers of drilling. And then place a series of instruments down that hole that will help us measure all of these things that we want to know, in terms of how the stresses are accumulating. How much stress there is. Whether it varies over time between earthquakes or only slowly accumulates. That's important for our hypothesis about fault physics. And other things. 

So seismometers, things called tilt meters that just measure is our bore hole slowly doing this, are parts of it doing that, but other parts staying vertical. Key questions like that. Cutting across these two major branches of the fault that we see in our seismic reflection images. Well it's great to record all that stuff, but here's the top of our hole. Once the ship goes away that's down at the bottom of the ocean, right? So how do we get the data? That's a big problem. Well, there's two ways. And the standard way, the way that's been done for any hole like this, which there aren't very many, this is already a big technological challenge, is to have data loggers at the surface, record it, and come back with one of those submarines or an ROV, and just download the data. That's nice, but you don't get anything realtime, right? 

If an earthquake happened you wouldn't have any data until you had a chance to go back and get it with a submarine. So in a sort of allied project that the Japanese government is funding separately, and it's a domestic project in Japan. They are planning a network. Will my slide advance? There we go. They are planning a network of offshore fiber optic cables. something like submarine telephone cables, that will be able to be tied into a whole data gathering network in the same region of Japan. It turns out that because they are so interested in earthquakes here, they're planning to put a number of seismometers just on the bottom. And then our bore holes are kind the pinnacle of that whole operation. This hasn't started yet. 

But over the next five years they plan to distribute cables out. I don't know if you can tell this is the same area. And so the goal is to have the data from the these bore holes literally streaming onto the Internet by sometime in the next decade or so. Well, five or six years from now. But that's possibly optimistic based on budgets and other things. So that this really will be a wired plate boundary. You know, a subduction zone where we have data coming in. And even if the earthquake doesn't happen till I'm retired and, you know, long gone from this whole project, all the things that we can learn about the earthquake faults by what they do in between earthquakes is essential information. And we don't have it from anywhere in the world. There is a similar project going on, by the way, you might have heard of on the San Andreas faults in California. 

They've drilled a hole 3 kilometers down into the fault zone recently. You'd have to invite me back to talk about that one sometime. I'm a little bit involved in that project, too. But what we can learn in the San Andreas fault, what we can learn in a subduction zone are very complementary pieces of information to learn about how earthquakes really work. Okay, so I think I've actually kind of talked a little bit about the future plans. There is some more drilling of this sort of outer part starting in December. I probably won't be at sea for this. I'm one of the two chief scientists for the project. I'm not going to spend five months at a time on the a ship. So we have a team about 75 people who are involved, who come and go and do different things. 

I expect to go to sea in January for a few weeks as part of one of these things. We'll drill out in there. And then really, it's oh, yeah that's right. So that's going to come down. Really, it's 2010 to 2012 when we hope to put in our two very deep bore holes that are going to involve a real test of this new ship's drilling capability. I guess one of the things I didn't say up front was that the reason this ship is so much bigger than the other drill ships we had available to us, in part, is because it uses a technology called riser drilling. And I'd be happy to explain that afterwards. It's fundamentally a way that we can control the stresses and pressures in the bore hole well enough to get very deep below the surface. The standard technology we've had available to us can make a hole about one or one and a half kilometers deep. Then the bore holes become unstable and are just harder to deepen and you tend to get stuck, or worse. 

Yeah? 
- How many inches in diameter is your drill bit? 
- There are variable ones. Typically, the ones that we were using for all that logging oil drilling is 12-3/4. So, you know, it's about so big. That's actually a pretty good place for me to jump into this bit of video here, which I think will illustrate some of that. If I can get it to go right. In fact, since you asked about the drill bit, I'll jump ahead to that part first. Let's see if this works. It just takes it a second to fire up. 

It's on a DVD. I didn't have a chance to pull it off of there. Here we go. Okay, so this is actually the business part of the ship, the rig floor itself. And maybe you've seen, you know, rough necks handling chains and stuff on an oil rig. It doesn't look like that anymore. They look like they're playing a video game, essentially. But these guys are controlling the operations from within the driller's dog house here. It's all joysticks. There's the drill bit right there just being lowered through the rig floor itself, which is on the ship. 

On its way down 2,000 meters, just to hit the sea floor where it can start drilling the hole. So running down into the hole that way. It's a noisy place. Here's the top drive that runs that down. They take 120 feet, or so, 40 meters of pipe at a time, put it down. Then of course they have to screw another piece of pipe on. In fact, that's what showing right here. Two pieces of pipe being screwed together. All by this sort of remote controlled hydraulics system now. There's what's called the iron rough neck picking up the pipe, torquing it together and then running the next piece of pipe down into the hole. 

It's a phenomenal operation. I'm focused on the science side, but I'm fascinated by the sheer technology of handling this much steel. When the pipe is hanging and we have a full string hanging, we'll have a few hundred thousand pounds, easily, of steel hanging down. The largest winch, the largest drawworks in the world that have ever been built was put on this ship. There's been a bigger one built since then. But it's an enormous winch. This is the hole in the middle of the ship. If you're going to drill, you have to have a moon pool, right? That's what they call them. You have to have a place where there's water in the middle of the ship. 

There's the drill pipe hanging down into the water just below, just below the rig floor there. I don't know how well you can see it. And now here's the video image from the remote submarine. Here's the drill bit approaching the bottom of the ocean. In fact, there's the sea floor. You can see the cloud of mud stirred up by all of this stuff happening. That's 2 kilometers down in the water. We often would see a very strange biology. And it's very diverting, you know. We're all geologists, but the fish are a lot cooler to look at than the mud at the sea bottom, I have to admit. 

And here's the drill pipe when it's actually drilling a hole. So the bit's now down somewhere in the bottom. It's churning things up. These are some of those logging tools. So it's only in a few meters at this point. We can see it all realtime on the ship. We're sitting there in our air conditioned environment watching all this happen below us. Here's the drill pipe actually drilling when it's deep. And I don't know if you can see this or not. It's actually sticking and slipping. 

It's turning up on the ship continuously. Down there, may be you couldn't see it. But it was stopping, and then spinning a lot. And that's because there's a lot of fiction at the drill bit. That's actually bad. We don't like that to happen. That's a sign that you could get stuck. 
(inaudible)
 Yeah, I'll tell you a story at the end about the stick slip that was going on, actually, when that video was happening. I'll jump to just a little bit of the picture of what the ship looks like at a big scale here. 

Tom, tell me if I need to just call it quits. 
(inaudible)
 I'll just talk for a couple of more minutes. I really want to take some time to answer questions, too. This was actually we were leaving port. Somewhere in there, I'm standing on that helicopter deck. But it gives you that sense of the scale of the ship. The port was in Japan. And when we left, it was a big deal. This was the first expedition of this new ship. 

We had four helicopters circling us from TV news. We were on national news in Japan multiple times. We had news crews coming out and visiting us some of the time we were out there. 
- When you detract the drill bit, how do you get back into the hole again? 
- Oh, that's another fantastic piece of technology. Okay, basically if you pull out of the hole, but you want to use that same hole, you've got to be able to find it again, right? So what they do is they make up a big, essentially, gigantic funnel. It's about 12 feet across or so. It's painted with a bulls eye on the inside. And it has some floats that come up off it that are reflectors for radar, or for sonar. 

They bolt it together around the drill pipe, and then literally just let it go. And it sinks down in the sea bed. It embeds itself into the mud. And then you pull out the drill bit, and you can come back to the same spot. In fact, it's relatively routine to come back five years later, find the same place on the sea floor, get the ship to the same spot. You lower the bit down. And then your problem is how do you actually get that last few meters to get there. Because you can get close pretty easily. Nowadays, we have the luxury of these robot subs. In the past, they just had a TV camera they could send down. 

So they watch the bit with the sub, and then we have to move it around until it's right over that thing. And you can stab it into the sea floor, right, or into the funnel. And the problem is how do you move the bit? You can't drive the bit. All of can do is drive the ship, which is way up there. And it's got a couple of miles of steel pipe hanging down from it. Well, a steel pipe seems pretty rigid, except it's not rigid at all. It's like piece of spaghetti when it's hanging in the water, cooked spaghetti. So you move the ship three meters this way, and then you watch can the camera while this thing slowly comes over. And you try to get to where you're just on top of it. 

And we all watch on TV while these guys are edging around for three hours, or something like that. And we're all going nuts. And finally they stab it down in there. And they pretty reliably can re-enter those holes. Yeah, it's amazing stuff. Some of these holes have been deepened over multiple expeditions over a number of years. The deepest science hole in the ocean is a famous one out on the East Pacific Rise area, known to all of us as hole 504B. That doesn't say very much. It's 2. 2 kilometers down into the oceanic crust, so the pillow lavas, the basalts of the sea floor. 

Let's see. Okay, so I said I would tell a little story. I mean, things don't all go swimmingly, let's just say. And we did do some drilling. Let me jump back to the power point. We did do some drilling. Well, this will suffice actually. One of the holes that we tried to drill was this one labeled COO3 here, okay? Maybe that's a little small to see it, but basically our target was this blue fault down here. COO3 was supposed to go a thousand meters into the subsurface. 

And it doesn't. You can see it stops right there, actually hundreds of meters shy of our target. Well, the reason is we were drilling. And you remember that stick slip. We got good and stuck in the bore hole. It turns out that drilling into active earthquake faults is a good way to drill into very unstable places in the earth. The rocks in the bore hole start to collapse, because they're under a lot of stress. They have a lot of fractures in them. They collapse around them. Just like when your Makita gets stuck sometimes if you try to make too deep a hole in a piece of wood or something. 

The bit would get stuck. We're still trying to turn up here. The drillers are working hard, sweating, using a lot of language. And they're trying to get unstuck. You should see it. They'll pull up and down, move meters up and down. But you can see from the camera that nothing's happening at the sea floor. You're just stretching that steel. And yeah. They're watching all the gauges very carefully. 

They know the tensile strength of everything. They know the torques. But they don't know it well enough apparently, or whatever. It's a difficult situation, because they severed the drill pipe 200 meters below the sea floor. So we had 300 meters of pipe down there below the sea floor. It had about $3 million worth of logging equipment built into that drill pipe, some of those same things that I showed a picture of. And it was, you know, lost at sea. Well, it was lost deep beneath the sea, actually. The problem was, that logging tool had a hard radioactive source in it, a neutron source. That's the standard method used to measure the porosity of the rocks, because water, you know, absorbs neutrons, that creates back scatter. 

So you're not suppose to leave something like that behind, especially it turns out in Japan. They have very strict laws about, you sort of can't lose these sources. In the oil industry, it actually happens quite often. And there are procedures for dealing with it. But the procedures for dealing with it include what they call fishing. So fishing is even worse than just trying to get back into the same hole. You have to get back into the same hole with kind of a grappling device to try to catch the top of that broken bit, and figure out how to pull it back out. Well, we spent seven days on it. We knew from the beginning, it was a futile fishing expedition to try to get back that radioactive source from the hole. It turns out that we ultimately did what was I'm sure the very best thing to do, which is put 300 meters of cement on top of it. 

It turns out they're not very large or very strong sources. And there are hundreds of them embedded in both land and sea around the world, because of these kinds of operations, probably thousands of them embedded, especially in places like West Texas. But we did have to entomb it below the sea floor. And I don't think this was too close to where Godzilla was born in the movies. But we did cause a little bit of a incident that caused some concern in Japan. That's just, drilling is like that. And I've been on a number of drilling expeditions over the course of my whole career, including when I was a graduate student. We've left tons of hardware on the sea floor. It's just part of the game, unfortunately. And it's expensive hardware. 

But actually if you think about it, a couple of million dollars worth of equipment seven days of fishing at $200,000 a day just to run the ship, fishing quickly becomes not really worth it, right? Getting back something, even something that costs half a million bucks, is not worth a whole lot of your time and effort at that kind of rate. Okay, I've indulged your time. Let's just move ahead here. That takes a second. I'm not sure. Oh, yes. I already talked about that. So maybe I'll stop with this one, just some highlights of what we did. This was really made for a press conference slide that we taught. 

But, you know, 71 scientists from 12 countries were on board, not all of them for five months, in rotation. And we drilled all of these different sites. It's really the first time that we've been able to start accessing this environment. But we're really just getting started. It's obviously not just a UW-Madison project. You know, some of my grad students are involved. One of my post-doctorate researchers is involved. But this is many, many people from all over the world working together. So it's kind of a NASA scale, or an international space station scale project. Although unfortunately we don't get their kind of budgets. 

Now that's real. Now you're talking real money. But we're very excited about doing this program. We hope that it not only has fundamental science benefits, but also societal benefits in understanding these earthquakes and tsunami processes much better. And with that I want to thank you for your time. I'm happy to answer questions. 
(applause)
 Yeah? 
- Your drill bit that you told us about down there, what kind of material is that made out of, like carbide, for example? 
- Yeah, there's a variety. 

Oh, yeah, the question was what are the drill bits made of. What do you drill with? And it turns out it depends on what you're drilling into. We're drilling into relatively soft sediments. They don't have to be extremely strong. They're often carbide. They're tool steel, things like that. The drill bits that we're using have big teeth on them, and that's about it. They're called roller cone bits. Actually, that's not true. 

We were using a different type. Anyway, they're made to basically sort of just chew up the rock, grind it up. And then that mud we pumped down flushes it out of the bore hole and up to the surface. If you're drilling in hard rock, you actually use bits that are not such hard steel, but have diamonds embedded in them, just like a rock cutting saw is. And you're doing the same thing you do with a concrete saw or a diamond saw to cut that rock up. Go ahead. 
- You said there's problems with the pressure of drilling that low, it's kind of a new thing to overcome. How is that different then, you know, typical oil drilling at sea like that? Are there different challenges? 
- He asked me how the kind of drilling we're doing is different from the typical oil drilling that gets done at sea. 

In some ways, some of the challenges are kind of the same. We select our sites really carefully not to accidentally discover oil. It's actually really important that we drill totally uneconomically valuable wells. And the reason is, of course, we don't want a blow out type of situation. We're not really out there equipped for shutting in a high-pressure gas pocket, or something like that. We are equipped for it, but it's a situation we don't want to get into. So we do a lot of planning to make sure we're basically drilling the worst possible oil wells of all time. You know, and we have a fantastic record. There are more than 1,000 ODP sites in the world. And not one of them has been anything but a dry hole to the oil industry types. 

On the other hand, we're drilling into these high water pressure areas. And it is challenging. When they drill oil wells, they're typically, actually, not that interested in the upper few hundred meters that, for us, was actually was kind of important in this thing. So they'll slap in a bunch of that drill casing and then often go much deeper. And honestly, what we're doing from the drilling technology side, is not even close to what they're doing in the off shore for oil drilling. I don't know if you guys know this, a typical oil well in the deepwater Gulf of Mexico, they start by going down a mile, or so, or two, and then turn horizontally. And it's not uncommon to go three or four miles out laterally, and hit a pocket that is no bigger than say the volume of this room we're sitting in right here. That's because they have fantastic seismic reflection data. They have all kinds of those logging tools that they're monitoring in realtime to try to hit that sweet spot for them. And it's not that uncommon for a well in the deepwater offshore to cost, a single well, to cost $50 million, $60 million or $80 million to drill. 

Not uncommon at all. And, of course, they make money. They're making money hand over fist right? So it must be worth it. But those offshore wells are tremendously expensive. Yeah? 
- This is a naive question. You refer to below the sea floor, why aren't these tectonic plates at the sea floor level? 
- Yeah, well technically, of course they are. The question was, why am I talking about going deep beneath the sea floor? 

Why aren't the tectonic plates right at the sea floor? And if you think of that cross section. So here's the boundary between the two plates, and the sea floor is up here. They come all the way up to the surface, in the sense that there is a deep sea trench. We know where that subduction zone is. But when the slip is happening on the fault during an earthquake, it might be a very large slip, tens of feet down deep. It tends to die out towards the surface, except that sometimes it doesn't. It runs all the way up to the surface and we have rupture all the way to a fault break on the sea floor. We're trying to identify whether these are like that or not. But when you get very close to the surface, the sea floor in that case, then it's kind of like a fault rupturing through this soil, the dirt in your backyard. 

It's not under enough pressure to really have a lot of that stress that releases seismic waves in an earthquake. So the stuff that's really close to the surface isn't really of interest to us. We need the place where they're under enough temperature, enough pressure to really be important for making earthquakes. It's also hard to find them, because the sea floor is blanketed with mud. And despite of all my fancy pictures of what's on the sea bed, and everything else, most of it is totally unexplored right? Even an area like this that we've intensively studied, no human being has ever seen 98% of the sea bed. We've seen little tiny bits and pieces of it where we can get down to it with a submarine. We have those seismic reflection images, but they don't give us the resolution to actually see say an individual fault break right at the sea floor, a fault scarp or something like that. So that's why, really. In the back. 

- You're doing this work, and maybe ever 90 years, or whatever the range is, it gets wrecked because of another earthquake, right? 
- Yeah, I really hope that my instruments get destroyed in a big earthquake in some ways. Well, that's right. I mean, the risk is, if we're installing all this stuff and the earthquake happens. If it actually slips through our bore hole area, and we suddenly have meters of, you know, break, then we're likely to lose everything that we have down there, or maybe a portion of it. One of our goals is to instrument, you know, above the fault zones, and below, and have things that might survive up above. But the key thing is for recording everything that's happening right up until that moment. Because if we're interested in precursors, precursory phenomena that might be coming as an earthquake is preparing to let go, then that's the data that we most want. So hopefully, even if our instruments all die, they die right at that moment where we just learned the most important thing. But really, that's part of the reason why the fundamental scientific objectives are not catching the great earthquake. 

I mean, that's nice. We want to do that. We'd love to hope that our experiment is still going on 20, 30, 40, 50, who knows how many years from now. But the fundamental goal is to look at the faults as they are right now. There's whole very complex science of fault physics that I haven't talked about hardly at all, that various key measurements will make. It will be like having, you know essentially a field laboratory, excuse me, for understanding those faults. We don't need the big earthquake to understand the faults better than we do today. I guess that's my point. Yeah? 
- What would be the deepest hole that's been dug into the earth, and what was the temperature at that point? 

- The deepest hole that's been drilled, as far as I know, is one that was drilled in the Soviet Union, in the old Soviet Union days actually. It's called the Kola Well. And it's I think 11 kilometers deep, 11,000 meters deep. It's on the continent. It's down into some granite. And from my perspective, it's drilled in one of the most boring places on the planet. It's just granite for 11 kilometers. That's not quite true. I'm exaggerating. I don't know the temperature at the bottom of that hole off the top of my head. 

But the second deepest hole is one in Germany. And it was drilled about 9 kilometers deep. And the temperature at the bottom of it was quite hot, something like 400 degrees C. And, in fact, they can't run a lot of these instruments down to those holes, because you can't build electronics that will survive very long, basically, at the temperature of a pizza oven, you know, or hotter in fact. So that's an issue. One of the things that's a technological challenge for this project is long-term instrumentation. Some of those instruments I showed in a nice picture don't actually exist yet. Because we predict the temperature at the bottom of that deep hole to be somewhere between 130 and 160 C. And that's pretty hot for a lot of electronic systems. There's actually a huge, you know, set of engineering developments going on for all kinds of things, from instrumenting jet engines to geothermal wells. 

People are trying to build high-temperature sensors. But it's not an easy thing. Yeah, go ahead. 
- What are some of the 12 countries that participate? And do you try to get as many countries? 
- Yeah, the invitation is certainly open to any country that's willing to pony up some money. But the U. S. and Japan and a consortium of European countries are sort of three co-equals, in terms of bringing in these various ships and paying for the program. European countries are like the UK, Germany, France, Italy, Spain is involved, several of the Scandinavian countries. 

Canada's involved in the program, although not as much as the scientists from Canada would like. They've only been able put in a little money in, which means only a few of the scientists get to go, which it too bad. There's a lot of great Canadian scientists who would like to participate. South Korea's involved. China just became involved in the program. And Australia's involved. I'm sure I left a few out. Something like that, yeah. Go ahead. 
- Where's the equipment made? 

- Oh, that's variable for all over the world. That ship was built in Japan. And quite frankly, it was a science initiative. But like a lot of the things in the U.S., it was at least partly not exactly a pork barrel project, but let's say an economic stimulus package for the ship yards, you know? The government approved it, I'm sure, because they want to learn about earthquakes and other things, but they also approved it because they want to give this really big contract to Mitsubishi Engineering. It was built at a cost of about $600 million. And that part was all Japan's money. That's not actually mingled international funds. Everything else comes, you know, the equipment a lot of it is directly adapted from the oil world. So a lot of it comes from Texas, or from Norway, or from wherever they build that. 

The American drilling ship, the one that the National Science Foundation operates, is currently being overhauled in a shipyard and Singapore. This is a worldwide industry that we're tapping into, yeah. Go ahead. 
- How did you get a nice clean core sample out of the hole where that drill bit's been going in. 
- Actually, it's surprising. I wish I had a drill bit, although I wouldn't have been able to carry it here. So, how do you get a nice core sample out of the hole with that crazy looking big monster drill bit drilling away at it. Well, the drill bit has a central hole, and then it has these roller cones around the outside. And as they drill, in certain kinds of rock formation, the drill does tend to break everything up and you don't get much of a core. But in most rock types, and even relatively soft sediments, the central part will be left alone. 

So a coring bit is actually even larger than that 12-inch one. But it will totally destroy the rock over a range like this, but leave it intact down the middle. And we often do pretty well. 
- It's basically saving the hole of a doughnut? 
- Yeah, exactly. Exactly, you're drilling a doughnut and you're getting what's in the middle. And you don't get all the core in one thousand meter long shot. What we do is you drill away for about a 30-foot interval. It's a 9-meter interval. And then the core enters a kind of a barrel contraption, a pipe, that they can actually send a wire down through the whole drill pipe, catch onto the top of it, pull it up, take the core out and sort of reload the cartridge again, and send it back down there. 

Drill 9 more meters, pull that out. And it comes 9-meters by 9-meters. 
(inaudible)
 That depends on the water depth and stuff like that. But a few hours is fairly typical. Anywhere from 40 minutes to half a day, depending on how hard the rock is. 
(inaudible)
 Yeah, there you go. Well, those cores certainly cost a lot of money to get. And we treat them very preciously, which is why I only brought a ten-year-old one out here. 

Yeah? 
- First of all, do you have any biologists involved in this? And how deep into these cores are you able to detect bacteria living into the rock? 
- That's a great question. I didn't bring it up, because it's sort of not central to the main part of this story. But there were in fact microbiologists on board for all the coring parts of this expedition. And they've been involved with lots of the ocean drilling work for the last decade or so. There's bacteria everywhere, until you reach a temperature of about 110 C, or so. With pressure, you can keep liquid water, you know, down to that kind of temperature. I think the people who study those thermophilic bacteria have found them up to, what is it, 113, and maybe 121 is still disputed. 

I don't know I'm not a biologist. Maybe someone in the room knows. They're not present in very large numbers, you know. But they're present. And in fact, their abundances vary depending on a lot of really interesting things about the geochemistry of the water. The pore sizes and shapes. One of the actually kind of exciting results that came out of this is we drilled in one area where unexpectedly, there were quite kind of course gravels in the core, so big pebbles the size of stuff you might use as ornamental gravel in your yard that are deposits of some of these deep sea, what are called turbidity currents, density flows. And those gravels are very porous. And they found huge bacterial populations living in that. 
- How deep was that? 

- That particular thing was maybe several hundred meters, 300 or 400-meters, I think, where the gravels were found. But the depth to find bacteria just depends on the temperature gradient. And it's very possible. I don't remember what the deepest where bacteria have been identified below the sea floor. But I would guess it's probably about a thousand meters or more. Basically, anywhere where it's cool enough, you're probably going to find some evidence that stuff's living down there. Yeah? 
- Do you have to worry about whales when you go to these sites? 
- Well, whales have more to worry about than us in Japan it turns out. 
(laughter)

 But that's a flip answer. But no, especially when those seismic reflection surveys are taking place, because they're sending out these pulses, these bangs in the water, they have protocols. There's whale spotters on board. They bring up the guns. They're called air guns, that make the pulses in the water. They bring up their amplitude, sort of ramp them up over a period of time. And what's been observed is the whales move out of the area if they're there. What's also been observed is sometimes they seem to hang around and are curious about it. There's a lot of debate. It's fairly controversial, whether any of this a damaging to marine mammals or not. 

I'm probably the wrong person to answer the question, since I have a vested interest in imaging below the sea floor. But it's not at all clear that it is. Some of the high frequency sonars, like the stuff the Navy's gotten in trouble for using around marine mammals, clearly operates in the range where their echo location is happening. And other stuff that looks like there's some real evidence of potential harm to those animals. The seismic booms are much lower frequency. And it's very likely that we may be annoying those animals sometimes when that happens. But there's not a lot of evidence that, for example, they just immediately race off if this is in the area. It turns out that this region that we're working in, there literally are not a lot of whales around. We never saw dolphins and porpoises during drilling, or just being at sea without making a lot of noise in the water. What else can I tell you about that? 

Yeah, I'm personally comfortable with what we're doing from that perspective. Yeah? 
- What force do you apply to the drill bit when you're drilling? And does it bow out at all when you're drilling? Is it always completely straight? 
- If it bowed out, we'd be in trouble. Because one of the things about that mile long steel pipe is you cannot put that in compression. It will buckle. And that will be a way for it to fail very easily. So there's a lot of weight near the bottom. 

It's all hanging from the top. And almost all of that strain is in tension. And what they actually do, the way you control the weight that you put on the bit is just to, they never really set it down. It gets to the bottom, they start to feel the bottom and then they just let some of that hanging weight ease back a little bit. And they calculate the weight they're putting on the bit. It's just under its own self-weight. And you never go to where, you know, you're hanging zero from the top, not even close. You just let a little bit of weight on bit. And mostly, then it's just grinding away under a little bit of its own weight. But a drill string in compression is a bad, bad thing. 

- One more question. 
- Okay. 
- Are you anywhere close to developing a predictive formula based on the pressure building up, the density of the rock, all those other factors? 
- So a predictive formula for earthquakes, you mean? Yeah, I would say, no, we're not even close. We're at this point where we're just beginning to find ways to put some of these instruments into the near field for the earthquake faults. And there's a great deal of theory, there's a lot of laboratory experimentation in the field of friction and in rock friction. There's a just a plethora of various sort of conceptual models, and therefore then physical hypotheses for what the key parameters are. And the problem is it's very hard to sort those hypotheses right now, because we have no direct measurements of some of the fundamental things we want know. Nobody knows, for example, about just the spatial variation of stresses, or the temporal variation of stresses. 

Especially, once the dynamic rupture gets going. Once an earthquake starts to break, then it's a rapidly evolving phenomenon, right? It's a surface, but it has some volume. Water's being squirted everywhere. The rock is heating by friction. We know from geologic studies that some faults actually melt as they slip. And there's a type of rock deposit that's literally melt on a fault surface. You know, but it's not generated by a volcano. But most faults don't seem to melt, which actually runs counter to a whole class of hypotheses. Why don't they melt? 

We don't really have an answer. So I think that earthquake forecasting, the long-term forecasting, like the probability method, basically the weather forecast for earthquakes is improving. But it's on a decadal time scale. The question of if we know a spot is building up stress and we think it's at a high risk, is it going to have an earthquake next Thursday at 2:00 p.m., or 17 years from now on a different Tuesday at 4:00 p.m.? That kind of question. Yeah, or even at the scale of the next two weeks, there just isn't a fundamental model at this point. Yeah? 
- If you're going to have a earthquake at sea, is it better, you know, less damage if it's out in the middle, like in the deeper water, or if it's close to the shore? I know like, you know, as far as tsunamis. 

Most people get killed by the tsunamis right? 
- Absolutely, the tsunamis for these kinds of earthquakes are the most devastating part. Because the earthquake itself happens mostly under the ocean, there's strong ground shaking at the coast line, and that can be quite damaging. But typically it isn't so bad compared to continental earthquake. So it's the tsunami. And in general, yeah, of course if the tsunami is generated relatively close to land, as opposed to out in the middle of the ocean, then you're worse off when you're near to the original source of it. Because they do die out with distance. 
- To make a bigger wave. 
- But, yeah, you get a bigger wave close and eventually it dissipates. But there's a huge "but," and that is that tsunamis are extremely long wavelength waves. 

Wavelengths of hundreds of kilometers. And so, for example, when the Chilean earthquake happened in 1960, or when an Aleutian Islands earthquake happened in 1946, Hawaii was badly damaged by the tsunami that was that generated in both of those cases. It can travel across thousands of miles of open ocean and still be a pretty large wave, because it hasn't traveled very far relative to its wavelength, I guess is the point. That's the reason for these tsunami warning systems. And of course, we all saw it right? The damage from the Sumatra earthquake was by far the worst in northern Sumatra. That's where, you know, that whole city was virtually wiped out. Many other villages, 150,000 people lost their lives. But nearly a 100,000 lost their lives in Thailand, and in, you know, Sri Lanka, and in India, and all these places that were much further away. So the tsunami was still quite damaging there. 

- Your closed? 
- I'll keep going until you tell us to stop, I guess. 
(inaudible)
 People can certainly ask me stuff afterwards too. 
(applause)