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Regional Seismograph Networks in the United States

as of March 1988

22 NRC



(* indicates partial USGS support)

(# indicates full USGS support) (NRC or DOE indicates USGS operated with full support from that agency) 736 networks receive total support from the USGS 400 networks receive partial support from the USGS

77 networks are operated by USGS but are supported by either doE or NRC stations North-Eastern U.S. Seismic Network Lamont Doherty (Columbia University)

27 * Weston Observatory (Boston College)

29 Woodward Clyde Consultants

42 others


total 123 South-Eastern U.S. Seismic Network

Center for Earthquake Research (Memphis State University) 30
Georgia Institute of Technology

University of South Carolina (also USGS)
Virginia Tech
Tennessee Valley Authority



total 144 Central U.S. Seismic Networks St. Louis University

37 * Oklahoma Geophysical Observatory

University of Michigan


total 78 Great Basin, Intermountain, and Rocky Mountain Networks University of Utah

75 * University of Nevada, Reno

65 % U.S. Geological Survey Southern Nevada (Denver, co)

55 DOE others


total 260 California Seismic Networks USGS Central and Northern Calif.

360 # USGS - California Institute of Tech. Southern Calif. 240 # University of California, Berkeley

20 University of Southern California

30 * others


total 725 Northwestern U.S. Seismic Networks University of Washington USGS Network

110 * North American Rockwell


total 140 Alaskan Seismic Networks U.S. Geological Survey (Menlo Park, ca)

64# University of Alaska

36 * Lamont Doherty (Columbia University)

20 * Ålaska Tsunami Warning Center

15 CIRIES (Boulder, CO)

11 # total

147 Hawaii Seismic Networks Hawaiian Volcano Observatory (USGS)

60 # Pacific Tsunami warning Center (Noaa!

10 70

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Approximate total number of stations in u.s. regional networks


Mr. YATES. Order of magnitude-what?
Dr. MORGAN. About 400 run by us, and by-

Mr. YATES. Now, is this less in number than you had, say, five years ago?

Dr. MORGAN. Yes, somewhat.

Mr. YATES. Well, how many do you need for what you would consider to be reasonably adequate coverage?

Dr. MORGAN. Well, in order to have adequate coverage, we have to do a number of operations, including seismic stations, strain gauge studies, and very detailed fault mapping.

Mr. YATES. Have you not been cutting those back over the last five years?

Dr. MORGAN. Some of that has been cut back, yes.

Mr. YATES. Now why-is this just budgetary? Or can you get along without the money?

Dr. MORGAN. Primarily, we cut back on those areas that are the longest term risk in terms of scientific investigations. This has to do with prediction. We try to concentrate on studies related to mitigation of the effects of earthquakes. This is by studying exactly where the faults are, where their periodicities are -

Mr. YaTEs. Have your studies been excessive?
Dr. MORGAN. No, we have not felt they were excessive.
Dr. PECK. Primarily it's a budgetary matter, Mr. Chairman.

Mr. YATES. Well, what should your program be-here you've got-how much of a threat do you have there?

You were starting to say, Dallas, that you have a prediction of a major earthquake at some time within the next 30 years. Is that correct?

Dr. PECK. Yes.
Mr. YATES. It could happen within the next 30 days, couldn't it?
Dr. PECK. That's right.
Mr. YATES. Okay.
Dr. PECK. Yes, Mr. Chairman.

Mr. YATES. And are you ready? Suppose it were to happen-what would be the result? If you do have that danger, are you doing everything that you should be doing in order to be in a position to warn the people of the region so that they can protect themselves against death and destruction and injury?

Dr. MORGAN. We've done quite a lot, and we've been working with

Mr. Yates. Well, you've done as well as you can within the budgetary allowances that you've had.

Dr. MORGAN. Yes. And we've also-

Mr. YATES. Are you doing as well as you should do assuming that you had more funds available?

Dr. MORGAN. No. Mr. YATES. All right. What should you be doing, if you had more funds available? Dr. MORGAN. We learned from the Whittier Narrows earthquake, which was in the central part

of the Los Angeles area, that we and our colleagues at Southern California University and at Caltech were not prepared in an operational sense to respond to a major local earthquake.

Mr. YATES. Why were you not?

Dr. MORGAN. The staff was not adequate, the instruments clipped so that the signals were not received completely.

Mr. YATES. If you are not ready, is the State of California taking your place? Are they-

Dr. MORGAN. No, we work in a very good and complimentary way with the state.

Mr. YATES. What the Committee is interested in is whether there is adequate preparation for notification of a catastrophe impending by all the agencies, State, Federal and local, in the area. Can you tell us whether there is, or whether the budgetary problems have restricted the kind of surveillance that you should have?

Dr. MORGAN. I don't think that the present surveillance is adequate.

Mr. YATES. All right, then. Where is it inadequate, and how much more money should you be having?

Dr. MORGAN. Well, you asked earlier about a wish list. Second on may wish list is-

Mr. YATES. Well, I'm not talking about a wish list now. Although that may come later.

What I want to find out now is where this is inadequate, both in terms of what you should be doing and the amount of money that's available.

EARTHQUAKE HAZARDS REDUCTION PROGRAM Dr. MORGAN. With the amount of money available, Mr. Chairman, we will be doing the absolutely necessary monitoring in the seismic stations of Southern California and in the geodetic systems. But they will be at the absolute minimum that we feel we can carry on with.

Mr. YATES. All right, the absolute minimum.

In other words, it would be irresponsible to cut that program any more. If we cut any further, we would have to decrease major segments of study. Isn't that what you said about your cuts previously?

Have you not been cut back because of previous budgetary reductions on what you consider to be necessary preparations?

Dr. MORGAN. The program is generally divided into studying mitigation of earthquakes plus their prediction. So the area where we've taken the major cuts is prediction of earthquakes.

We're really trying to assess what the effects of an earthquake would be and trying to warn the local communities on what to do.

Mr. YATES. Okay.
Is that because prediction is not an absolute science?
Dr. MORGAN. That's correct.
Mr. YATES. Okay.

Dr. MORGAN. So an important element of our program continues to be

Mr. YATES. Well, before you move into that, I think that I remember your testifying that your experience in China was such that you decided that even though they hit the target a couple of times, you still feel it isn't an absolute science.

Dr. MORGAN. That's very true, Mr. Chairman.

Mr. YATES. Does that mean we shouldn't be doing any of that? If it's not an absolute science, why are you doing any of it?

Dr. PECK. I think the term not an absolute science is perhaps not the best phrase.

We don't understand yet exactly what the process is, nor are we in a position with certainty to predict a future earthquake. But there have been successes both by the Russians and the Chinese using phenomena such as changes of levels in water wells or in deformation in order to predict an earthquake.

The Japanese have a major operational earthquake prediction network manned 24 hours a day, because they have the confidence that in some areas of Japan, they have the background information to be able to predict an earthquake.

Mr. YATES. Well, now, why do they think that they can do it, and you don't think they can do it?

Dr. PECK. Yes, I think they probably can do it.
Every area is different, just like-

Mr. YATES. Well, how much different is their area from California?

Dr. PECK. Their area is different because they are-Tokyo is sitting on top of a downgoing slab, and the earthquakes and the de formation of the ground are very different from that in California, where you have two plates sliding.

Mr. YATES. Okay.
Which is the more dangerous condition?
Dr. PECK. Each one is a very dangerous condition. But the
Mr. YATES. Then why are the--
Dr. PECK. The phenomena are different.
Mr. YATES. Then why are the Japanese doing more than we are?

Dr. PECK. They and the Chinese have placed a greater stress in their Government on earthquake prediction and earthquake hazards.

Mr. YATES. Well, is their hazard any less than ours?
Dr. PECK. Well, it's like Japan was all California.
Mr. YATES. Okay.
Dr. MORGAN. So that the earthquake hazard is—
Mr. YATES. It's a national interest.

Dr. MORGAN. It's a national one, more so than it is in the United States. It's a national problem in the United States, too, but less so than in Japan.

Mr. YATES. Well, is the condition in California the equivalent of the condition in Japan? Dr. MORGAN. It's equally frightening.

Mr. YATES. So that to the people of California, they should have the same attitude towards the danger as the people of Japan have.

Dr. MORGAN. Absolutely.

And there are segments of the faults in California that we feel have a 50 percent probability of breaking in the next 30 years.

Mr. YATES. Then why don't we do that? The fact that it's not national doesn't mean that we shouldn't be paying attention to one part of the nation.

Dr. MORGAN. I might say that there are other areas of the United States that are subject to severe earthquakes.

Mr. YATES. Could you tell us which ones those are?

Dr. MORGAN. The New Madrid area in the central part of the United States.

Mr. YATES. The which area?

Dr. MORGAN. The Mississippi delta and the Mississippi valley, that section in the central United States. Charleston has been rocked by severe earthquakes. In the past they've had some.

Dr. Peck. The poster there shows the likelihood of strong ground shaking around the country. The intense colors are where there is a greater hazard. You see one area along the Mississippi River where the-

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