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Dr. Hess. No. They don't have the capability to do the one at sea, and so in view of that they are doing this very deep one on land.
Senator ELLENDER. That is what a lot of people thought about their capability with Sputnik.
Dr. Hess. They might still do it at sea, but they certainly can't do it on land.
Senator MAGNUSON. On the 50,000 feet—the area where the Russians intend to bore this hole, are you saying to us that they are going to have to go beyond the 50,000 feet?
Dr. Hess. They have to go to twice that to get through the crust. They don't really intend to get through the crust.
Senator ELLENDER. Assuming that you do complete this job, what do you expect out of it?
Ďr. Hess. A great advance in technology of drilling. I think that is probably economically the most important single thing.
Senator ELLENDER. Won't it more or less satisfy the curiosity of men like yourself and others who are studying geology?
Dr. Hess. That certainly would be a considerable factor, yes, sir.
Senator ELLENDER. So that it may be something to perhaps satisfy the vanity of a lot of theorists?
Dr. Hess. Oh, I wouldn't say that.
Senator ELLENDER. I have supported this in the past, and I am very seriously thinking of looking into it further in the future. But unless we can get a more or less firm contract indicating the cost of it to be a number of dollars, my fear is that we might be spending much more than this $110 or $120 that is now in comtemplation.
Senator YOUNG. Mr. Chairman?
DEPTH OF OCEAN AND DRILLING CAPACITY
Senator Young. How deep is the ocean where you expect to do this drilling?
Dr. Hess. About 14,000 or 15,000 feet. Senator Young. What do you believe is below the crust of the earth when you get down there? What is the scientific viewpoint on it? It is a long way down there, I have often wondered myself what is in this.
Dr. Hess. By indirect means we know-
Dr. Hess. 150 centigrades at this place, not terribly hot, but we can drill the hole in a place that is hotter than usual. We can determine that by the heat flow from the bottom into the ocean. It is a rather easy measure to make, sticking a thermometer down about 10 feet into the underlying sediment. You can measure the temperature difference and in this way get heat flow.
The materials below the crust are silicates. We can guess that much. We know the density approximately at 3.2 or 3. We know the sound velocity. That is where wet get most of our information.
Senator MAGNUSON. Any further questions?
Senator ELLENDER. How deep is the earth's surface from where you are going to start the hole?
Dr. Hess. The water at sea level it is 14,000 feet to the bottom.
Dr. Hess. The deepest hole on land today is about 36,000 feet in Texas.
Senator ELLENDER. Has there been any survey of sites on land that would indicate that this project could be land based?
Dr. Hess. Yes, sir. Dr. Woollard, who is also going to testify here, has been engaged in this sort of study for the past 15 or 20 years.
Senator ELLENDER. Thank you.
STATEMENT OF DR. G. P. WOOLLARD, AMERICAN GEOPHYSICAL
UNION, HONOLULU, HAWAII
EARTH CRUST THICKNESS VARIATIONS
Senator MAGNUSON. All right, Dr. Woollard of the American Geophysical Union from Honolulu, Hawaii.
Dr. WOOLLARD. Mr. (hairman, I do not have any prepared testimony because I have been flying for the last 15 hours in order to arrive at these hearings and, before that, I was in a budget crisis of my own so I will be able to give this to you probably tomorrow in terms of a prepared statement if you decide it is necessary.
Senator MAGNUSON. We will leave the record open and you may place in the record whatever you wish.
Dr. WOOLLARD. Fine.
Dr. WOOLLARD. I can answer some questions and I would like to make a few comments, if I may.
Senator MAGNUSON. All right.
Dr. WOOLLARD. Regarding the thickness of the crust, it has variations. We find that the crust essentially, if you visualize it like you would
say blocks of wood at different density, balsam, white pine and oak, floating in a bathtub, the surface elevation is a function of the thickness of the block, and its density.
The places where we have material of the same density, say a mountain, the Rocky Mountains, it has a very thick crust beneath it, and it stands high, just like a thick block of wood would stand high and has a big submerged root, like an iceberg.
Where you are at low elevation like in the midcontinent, the crust is thinner. Now in going from the midcontinent region, let's say Iowa to Colorado, there is an increase in crustal thickness of some 15 kilometers. You go from a value of around 35 kilometers in Iowa to something of around the order of 50 kilometers in going under the rock in the Rocky Mountains. The thickness crust, that we know, and this is again from controlled seismic measurements where you make your own earthquakes and record over distances of 350 miles is of the order of 20 kilometers and that is a questionable measurement. This is in the San Joaquin Valley in California. Everywhere else we don't get anything thinner than 30 kilometers and there is a big question mark on this 20 kilometers.
Now 20 kilometers, we are still talking in terms of 65,000 feet plus drilling, which is beyond our capabilities. Also it is in a bad area from the standpoint of temperature. As you know, in southern California in the Salton Sea area, we have developed this thermal power, from drilling to hot water that has been converted to steam.
In Mexico, just across the border, they have steam coming out there at, I think it is something in the order of 10,000 pounds per square inch. This kind of area is not an area where you want to start drilling, obviously, so that this more or less rules it out.
This is a young tetronic area, where you have had a lot of volcanism in recent geologic time and where the rocks are still very high, so that this rules out any place on the continent. Now going back to your question.
Now, going back to your question regarding the Russians, the Russians were planning 15 holes.
Senator ELLENDER. It was not mine, it was the professor who said that. I just quoted.
Dr. WOOLLARD. Referring to this, he referred to one hole that they plan at 50,000 feet.
Now there is a possibility of the Russians maybe trying to do the same operation that we are doing. We don't know.
When I was in Moscow 2 years ago I saw seismic results, for example, of the Kurile Islands, which are the islands just immediately north of Japan, which indicated that they had a thin crust, something comparable to what we found off Hawaii, that might make a potential drilling site.
We know that they are continuing measurements in this area with the Pacific missile range hydraphone network, for example, with which we monitor everything that happens in the Pacific Ocean, and we see off Kamchatka in the Kurile area shot after shot, 5 minute sequences, 20 minute sequences, big shots, little shots. This says that someone is carrying out seismic refraction measurements probably related to the crust in that area.
But the Russians have announced nothing about the observations that I saw in Moscow 2 years ago. They have announced nothing about what they are doing at the present time. All we know is that they are doing something. They have been working in this area, and it is not inconceivable that they are thinking about putting an offshore rig similar to ours, but we don't know anything about this.
All we know is about their land program. There is one scheduled for the Kurile Islands. There is a 15-kilometer crust in the Kurile Islands. This is the only shallow one that they have scheduled, and 15 kilometers is still roughly four times the depth that we are talking about drilling north of Hawaii.
Now getting back to some basic concepts that disturb me a little bit, and this gets back to what led up to these hearings, and this has to do with what we call a reasonable return on investment. A lot of our investments we have to evaluate everything in investment in terms of dollars. The returns may or may not have a dollar value. When we look at the military budget, we don't put a dollar value on it. We talk about security. We stockpile our nuclear weapons for their deterrent value. We don't put dollars on it.
We educate our children beyond what we pay taxes for, not in terms of dollars. There are other intangibles. And the same thing applies to science. What do we get back out of it? You get direct and you get indirect benefits, and this is the part that I feel that we have not stressed enough.
NUCLEAR DETECTION AND EARTHQUAKE PREDICTION PROGRAMS We have this whole problem in the Mohole setup as a scientific operation, and yet the spinoff from this in terms of things that we are funding now, such as the nuclear detection program, the earthquake prediction program, the success of these, how good they are, how effective they are depends upon our knowing something about the mantle, a lot more than we know at the present time.
If we look at earthquakes, just as one example, we find that here are blocks. Here is the Colorado Plateau bounded by earthquakes on both sides, and rising. We have a history here of this thing coming up a mile since Neocene time. We have other areas over long periods of geologic time, such as Wisconsin coming up, Michigan going down, Illinois going down. I am talking about thousands of feet. This 12,000-foot relief between the same rock surface, in going from Illinois into Wisconsin.
UNKNOWN MANTLE OPERATION This mechanism that controls this is down in the mantle. It is not something that is happening in the crust. There is something that is happening in the mantle. We don't understand this. We even think that the Gulf of Mexico has got salt beds, salt domes on its botton, and yet we are talking about depths of water that are now in excess of 10,000 feet. How do you get salt that can only be formed by surface evaporation down 10,000 feet and being made into a big area such as the Gulf of Mexico?
We have got a fundamental mechanism here that we haven't the fog. giest idea as to what it is. All we can see is that when we carry out seismic measurements, we see these layers in the crust with different velocities, and then we hit this one which is worldwide, which we call the Mohole, a rather abrupt change.
Now, when we start trying to relate this to magnetic measurements, relate it to gravity measurements, relate it to heat flow measurements and look at regional changes in geology, the ages of the blocks that make up the continent, the mineralization, we see associated with different types of petrology, we realize there is something different about these areas, and all of it stems back to the mantle.
So all we do is end up with lots of questions. We are starting a program of planetary exploration. We are putting satellites in orbit around the Earth. We are taking remote sensors and we are seeing things. We are doing the same thing on the Moon. We are talking about doing it for Venus, Mars.
Senator ELLENDER. Jupiter, Saturn.
Dr. WOOLLARD. We see the perturbations in orbit in going around the Earth, big perturbations, not to destroy but to deform the geoid. We had a pear-shaped Earth, as you recall, only a few years ago. Last year this was modified to a four-cornered Earth from the satellite perturbations. We will end up with something you might call a warty tomato or potato before we get through with our satellite observations.
But these mass inequalities are all in the mantle. From what we see it looks like the base of the crust and the mantle are two phases of the same material. In other words, if you can change temperature and pressure or you can add or substract water, you can go from one physical condition to another physical condition. You can increase the volume and get to other densities. We don't know what this material is.
LABORATORY EXPERIMENTATION OF MANTLE SAMPLE REQUISITE
No matter how many rational explanations we come up with, until we get a sample of that stuff, take it into the laboratory, run controlled experiments on it to find out how it behaves under changing environment, we will never have the foggiest idea about what we are dealing with.
EARTHQUAKE PREDICTION We look at this business on earthquake prediction. Where do the earthquakes occur? We said on the boundaries. Where do they occur in terms of depth?
They occur in terms of the depth of the mantle at the Mohole. What is different there? You have plastic flow in one and rigid material in another, so you get different movements. Is this what is generating these earthquakes? Why do they occur at the mantle?
There is something very fundamental. In the nuclear detection thing, they have just come out with a map showing all of the area of the Western United States has got a very low velocity that biases all the time travel measurements for anything going up the western side of the Rocky Mountains as compared to what is happening east of the Rocky Mountains, again something relating to the Mohole.
We have got endless applications where we need this information, but we can't understand what we can get at the surface because we haven't got the foggiest idea what we are working with. We have no surface rocks that we can definitely say this is from the mantle.
We have made some wild guesses. We have run tests on them, but we still can't duplicate what we think we see. So we have got to get a sample, if we are going to have any real value in it, and it applies to, as I say, a lot of things.