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Seismograph ic Networks: Problems and Outlook for the 1980s Report of the Workshop on Seismographic Networks K e U i ^ t e ::⢠r, *.'*> Committee on Seismology nW"ch3-L/ ^,Commission on Physical Sciences, Mathematics, and * Resources National Research Council NAS-NAE NATIONAL ACADEMY PRESS f'f* .' ^1383 Washington, D.C. 1983 LIBRARY
C i NOTICE The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance. This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The National Research Council was established by the National Academy of Sciences in l9l6 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and of advising the federal government. The Council operates in accordance with general policies determined by the Academy under the authority of its congressional charter of l863, which establishes the Academy as a private, nonprofit, self-governing membership corporation. The Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in the conduct of their services to the government, the public, and the scientific and engineering communities. It is administered jointly by both Academies and the Institute of Medicine. The National Academy of Engineering and the Institute of Medicine were established in l964 and l970, respectively, under the charter of the National Academy of Sciences. Available from ^Geological Sciences Board National Research Council 2l0l Constitution Avenue Washington, D.C. 204l8
COMMITTEE ON SEISMOLOGY THOMAS V. McEVILLY, University of California, Berkeley, Chairman C. ALLIN CORNELL, Stanford University RICARDO DOBRY, Rensselaer Polytechnic Institute ROBERT B. HERRMANN, St. Louis University HIROO KANAMORI, California Institute of Technology FRANKLYN K. LEVIN, Exxon Production Research Company PAUL W. POMEROY, Rondout Associates PAUL G. RICHARDS, Lamont-Doherty Geological Observatory, Palisades DAVID W. SIMPSON, Lamont-Doherty Geological Observatory, Palisades ROBERT B. SMITH, University of Utah ROBERT E. WALLACE, U.S. Geological Survey, Menlo Park Liaison Members LEON L. BERATAN, U.S. Nuclear Regulatory Commission WILLIAM J. BEST, Air Force Office of Scientific Research MICHAEL A. CHINNERY, National Oceanic and Atmospheric Administration JOHN R. FILSON, U.S. Geological Survey EDWARD A. FLINN, National Aeronautics and Space Administration JOHN G. HEACOCK, Office of Naval Research LEONARD E. JOHNSON, National Science Foundation GEORGE A. KOLSTAD, U.S. Department of Energy PAUL F. KRUMPE, Agency for International Development JAMES F. LANDER, National Oceanic and Atmospheric Administration JAMES M. McDONALD, Office of Naval Research UGO MORELLI, Federal Emergency Management Agency iii
CARL F. ROMNEY, Defense Advanced Research Projects Agency EDWARD SCHREIBER, U.S. Department of Energy JOSEPH W. SIRY, National Aeronautics and Space Administration K. THIRUMALAI, National Science Foundation Staff JOSEPH W. BERG, JR. ROY E. HANSON iv
WORKSHOP ON SEISMOGRAPHIC NETWORKS: PARTICIPANTS THOMAS V. McEVILLY, Chairman Department of Geology and Geophysics -University of California Berkeley, CA C. ALLIN CORNELL Department of Civil Engineering Stanford University Stanford, CA PAUL C. JENNINGS Division of Engineering and Applied Science California Institute of Technology Pasadena, CA HIROO KANAMORI Seismological Laboratory 252-2l California Institute of Technology Pasadena, CA KAREN C. McNALLY Earth Science Board University of California Santa Cruz, CA PETER H. MOLNAR Department of Earth and Planetary Sciences 54-7l2 Massachusetts Institute of Technology Cambridge, MA PAUL G. RICHARDS Lamont-Doherty Geological Observatory Palisades, NY
ROBERT B. SMITH Department of Geology and Geophysics University of Utah Salt Lake City, UT Ex Officio Member KEIITI AKI Department of Earth and Planetary Sciences 54-526 Massachusetts Institute of Technology Cambridge, MA Liaison Members LEON L. BERATAN Chief, Earth Sciences Branch Division of Health, Siting and Waste Management U.S. Nuclear Regulatory Commission Washington, DC WILLIAM J. BEST Directorate of Physical and Geophysical Sciences Air Force Office of Scientific Research Boiling Air Force Base Washington, DC JOHN R. FILSON Chief, Office of Earthquake Studies U.S. Geological Survey Reston, VA LEONARD E. JOHNSON Program Director for Seismology and Deep Earth Structure Division of Earth Sciences National Science Foundation Washington, DC JAMES F. LANDER Deputy Director, National Geophysics and Solar-Terrestrial Data Center Environmental Data and Information Service National Oceanic and Atmospheric Administration Boulder, CO vi
Staff JOSEPH W. BERG, JR. Executive Secretary Committee on Seismology Commission on Physical Sciences, Mathematics, and Resources National Research Council Washington, DC ROY E. HANSON Senior Staff Officer Committee on Seismology Commission on Physical Sciences, Mathematics, and Resources National Research Council Washington, DC Guests SHELTON S. ALEXANDER Department of Geosciences Geophysics Program Pennsylvania State University University Park, PA THOMAS C. BACHE Program Manager Geophysical Sciences Division Defense Advanced Research Projects Agency Arlington, VA JOHN N. DAVIES Geophysical Institute University of Alaska Fairbanks, AK WILLIAM L. ELLSWORTH U.S. Geological Survey Menlo Park, CA E. ROBERT ENGDAHL Branch of Global Seismology U.S. Geological Survey Denver, CO vii
WALTER W. HAYS Office of Earthquake Studies U.S. Geological Survey Reston, VA ROBERT B. HERRMANN St. Louis University St. Louis, MO JEFFREY K. KIMBALL U.S. Nuclear Regulatory Washington, DC ANDREW J. MURPHY U.S. Nuclear Regulatory Washington, DC PAUL W. POMEROY Rondout Associates Stone Ridge, NY ROGER M. STEWART Office of Earthquake Studies U.S. Geological Survey Reston, VA viii
GEOLOGICAL SCIENCES BOARD WILLIAM R. DICKINSON, University of Arizona, Chairman SAMUEL S. ADAMS, Adams and Associates, Boulder, Colorado LLOYD S. CLUFF, Woodward-Clyde Consultants, San Francisco, California WALTER R. ECKELMANN, Exxon Corporation, New York MICHEL T. HALBOUTY, The Halbouty Center, Houston, Texas WILLIAM W. HAY, University of Colorado MELVIN, J. HILL, Gulf Oil Corporation, Houston, Texas CARROLL ANN HODGES, U.S. Geological Survey, Menlo Park, California WILLIAM C. LUTH, Sandia National Laboratories, Albuquerque, New Mexico CHARLES J. MANKIN, Oklahoma Geological Survey, Norman V. RAMA MURTHY, University of Minnesota, Minneapolis JACK E. OLIVER, Cornell University, Ithaca, New York STEPHEN C. PORTER, University of Washington, Seattle J. WILLIAM SCHOPF, University of California, Los Angeles E-AN ZEN, U.S. Geological Survey, Reston, Virginia Liaison Members LEON L. BERATAN, U.S. Nuclear Regulatory Commission ROBIN BRETT, National Science Foundation, Washington, D.C. (until September 30, l982) PHILIP COHEN, U.S. Geological Survey, Reston, Virginia KENNETH DAUGHERTY, Defense Mapping Agency, Washington, D.C. PAUL R. FISHER, U.S. Department of the Army BRUCE B. HANSHAW, U.S. Geological Survey, Reston, Virginia ix
JAMES F. HAYS, National Science Foundation, Washington, D.C. (from October l, l982) JOHN G. HEACOCK, Office of Naval Research LINN HOOVER, U.S. Geological Survey, Reston, Virginia GEORGE A. KOLSTAD, U.S. Department of Energy JOHN F. LANCE, National Science Foundation, Washington, D.C. DALLAS L. PECK, U.S. Geological Survey, Reston, Virginia MARK SETTLE, National Aeronautics and Space Administration, Washington, D.C. A. G. UNKLESBAY, American Geological Institute, Falls Church, Virginia KENNETH N. WEAVER, Maryland Geological Survey FRANK J. WOBBER, U.S. Department of Energy Ex Officio CLARENCE R. ALLEN, California Institute of Technology, Pasadena JOHN C. CROWELL, University of California, Santa Barbara Staff JOSEPH w. BERG, JR., Executive Secretary WILLIAM E. BENSON, Senior Staff Officer ROY E. HANSON, Senior Staff Officer
COMMISSION ON PHYSICAL SCIENCES, MATHEMATICS, AND RESOURCES HERBERT FRIEDMAN, National Research Council, Cochairman ROBERT M. WHITE, University Corporation for Atmospheric Research, Cochairman STANLEY I. AUERBACH, Oak Ridge National Laboratory ELKAN R. BLOUT, Harvard Medical School WILLIAM BROWDER, Princeton University BERNARD F. BURKE, Massachusetts Institute of Technology HERMAN CHERNOFF, Massachusetts Institute of Technology WALTER R. ECKELMANN, Exxon Corporation JOSEPH L. FISHER, Office of the Governor, Commonwealth of Virginia JAMES C. FLETCHER, University of Pittsburgh WILLIAM A. FOWLER, California Institute of Technology GERHART FRIEDLANDER, Brookhaven National Laboratory EDWARD A. FRIEMAN, Science Applications, Inc. EDWARD D. GOLDBERG, Scripps Institution of Oceanography KONRAD B. KRAUSKOPF, Stanford University CHARLES J. MANKIN, Oklahoma Geological Survey WALTER H. MUNK, University of California, San Diego NORTON NELSON, New York University Medical Center DANIEL A. OKUN, University of North Carolina GEORGE E. PAKE, Xerox Research Center CHARLES K. REED, National Research Council HOWARD E. SIMMONS, JR., E.I. du Pont de Nemours and Company, Inc. BATTEN S. YODER, JR., Carnegie Institution of Washington RAPHAEL G. RASPER, Executive Director xl
PREFACE Seismographic networks collect the data fundamental to the science of seismology, providing recordings of ground motion from natural earthquakes and other seismic sources ranging in size from the great earthquakes to the smallest detectable microearthquakes. This ground motion reveals the passage of seismic waves through the earth, and the waves may be recorded very close to the source or at great distances many minutes or hours after the event, having traversed paths that penetrate the entire earth. The data tell us much about the earth's interior structure and dynamics in addition to the nature of earthquakes. They allow identification of the type of source, explosion or earthquake, and they provide details of the seismic source process. These observations are important not only to the science of seismology but also, directly or indirectly, to society. For example, the earth's magnetic fieldâthe basis for navigation, for geophysical exploration, and for a geological time scaleâis generated mainly in the core, the structure of which is determined seismologically; the differentiation of explosions and earthquakes by seismic means is basic to monitoring a nuclear test ban treaty; seismic means are used to study inhomogeneities in the earth's mantle, which can lead to the discovery of mineral resources; the mitigation of seismic hazards for general construction and for critical facilities requires knowledge of both the locations of expected earthquakes and the nature of strong ground motion; and the search for methods of earthquake prediction relies heavily upon the existence of networks of closely spaced seismographic stations. Seismology is a young and vigorous science, and it is being called upon continually to address new problems. The laboratory of seismology is the earth, its data base constantly changing and its time scale set by geodynamic xiii
processes. The seismographic networks are the basic scientific tools, analogous to major telescopes in astronomy or particle accelerator facilities in physics, that provide the continuing data base for the science. It is very important, for this reason, to keep U.S.- supported seismographic networks in the best operating condition, to provide networks with the latest technology, and to improve constantly the management and data bases of the networks. These needs, unfortunately, have not always been met. The importance of observational data from seismographic networks has not been recognized consistently by decision makers allocating funds among competing programs. The various governmental agencies responsible for network operations encounter many difficulties in obtaining adequate funding for the maintenance, upgrading, and the research associated with these important national facilities. Even though the amounts of money needed are modest, crises in support funding seem to occur regularly, as short-term objectives change within the agencies. Unlike the otherwise analogous telescope or accelerator facilities, seismographic networks are made up of large numbers of individual, relatively small installations, necessarily distributed widely with respect to the features studied, and thus globally for many investigations. The broad perception of networks as facilities is consequently lacking, contributing to their vulnerability in times of financial stress. In addition, the ongoing process of upgrading involves simultaneous acquisition of new equipment for all stations in the network, including foreign installations in the global networks, and the consequences of this peculiarity in facility maintenance are not readily accepted by funding agencies. Given the extremely rapid rate of technological advance in the areas of data acquisition and processing, maintaining state-of-the-art capabilities in the seismographic networks is a difficult task indeed. This report is the result of a workshop convened at the request of several governmental agencies to review the status and associated problems of and the outlook for seismographic networks. Recommendations have been made to help solve the problems and to assure a viable observational capability for the future. If this is accomplished, the time and effort of the many contributing scientists will have produced a major contribution to the nation. Thomas V. McEvilly Chairman
AC KNOWLEDGMENT S This study was performed by the participants of the Workshop on Seismographic Networks under the aegis of the Committee on Seismology of the National Research Council's Commission on Physical Sciences, Mathematics, and Resources. The work of the Committee on Seismology is supported by the National Oceanic and Atmospheric Administration, U.S. Geological Survey, Air Force Office of Scientific Research, Nuclear Regulatory Commission, Office of Naval Research, Department of Energy, Federal Emergency Management Agency, Defense Advanced Research Projects Agency, and the National Science Foundation. The Committee on Seismology expresses its appreciation for the interest and support of these agencies. Forty-five operators of seismographic networks completed questionnaires for the participants of the workshop, and these provided many insights into operations and problems. xv
CONTENTS l EXECUTIVE SUMMARY l 2 INTRODUCTION 4 3 GLOBAL NETWORKS 7 4 REGIONAL NETWORKS l7 5 NATIONAL NETWORK 27 REFERENCES 30 APPENDIXES A GLOBAL NETWORK DATA 3l B REGIONAL NETWORKS: QUESTIONNAIRES, RESPONDENTS, SUMMARY 45 C SUMMARY AND MAJOR RECOMMENDATIONS OF U.S. EARTHQUAKE OBSERVATORIES: RECOMMENDATIONS FOR A NEW NATIONAL NETWORK 59 D GLOSSARY 62 xvii