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Global Earthquake Monitoring: ITS USES, POTENTIALS, AND SUPPORT REQUIREMENTS > Panel on Seismograph Networks Committee on Seismology â¢Assembly of Mathematical and Physical Sciences National Research Council NATIONAL ACADEMY OF SCIENCES Washington, D.C. 1977 NAS-NAE APR )2 t377 LIBRARY
NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Re- search 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 mem- bers 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. ISBN 0-309-02608-3 Library of Congress Catalog Card Number 77-52l9 Available from Printing and Publishing Office National Academy of Sciences 2l0l Constitution Avenue, N.W. Washington, D.C. 204l8 Printed in the United States of America Order from National Technic.il Information Service, Springfield, Va. 22161
PREFACE The long-term development and support of permanent seis- mograph networks must be a responsibility of government because of the magnitude, expense, and international nature of global earthquake monitoring. But in the United States, a stable federal program for such support does not exist. The U.S. program for global seismograph networks is frag- mented and suffers from the lack of a long-term funding plan, and these problems are even more serious in view of current research needs and recent technological advances in instrumentation and data processing that must be in- corporated into the Worldwide Standardized Seismograph Network (WWSSN). Global seismic networks are as basic to seismology as the telescope is to astronomy and the accelerator is to physics. Without this instrumentation, seismologists are "blind" to subsurface earth processes and properties and the very survival of the science would be threatened. Support of a modern global network of seismic stations is clearly in the national interest. In a little more than a decade, the WWSSN significantly increased our knowledge of earthquakes and of earth structure and dynamics while performing its initial mission of providing basic scienti- fic information for the detection and identification of underground nuclear explosions anywhere in the world. These major scientific advances provide important new in- put toward the solutions of such national problems as the monitoring of nuclear tests, earthquake hazard reduction, understanding the origin and location of minerals and geothermal energy sources, and the siting of dams and nuclear power plants. The Committee on Seismology has a continuing responsi- bility to provide scientific and technical advice to those responsible for the operation of the WWSSN and other
government-supported networks and arrays and for the conduct of research in seismology. As part of the Com- mittee's effort to carry out this responsibility, and in view of the long-standing problem of obtaining adequate and stable financial support for seismic data-gathering activities, it formed a Panel on Seismograph Networks to summarize and evaluate the state of the networks and arrays in the light of current and foreseeable needs of the users of seismological data and to recommend both remedial and future-directed actions to responsible gov- ernment decision makers and public officials. The Com- mittee recognized that substantial changes are to be expected soon in the responsibilities of federal agencies that have supported the networks and that its study should thus be undertaken at the earliest possible time. This report addresses the topics discussed above and presents the views of the earthquake seismologists who make up the Panel concerning improvements needed in global seismic networks if they are to be used effectively. The recommendations offered reflect these concerns, and national problems and goals were given the highest prior- ity in the Panel's deliberations. E. R. Engdahl, Chairman Panel on Seismograph Networks Committee on Seismology IV
ACKNOWLEDGMENTS This study was performed by the Panel on Seismograph Networks of the Committee on Seismology in the National Research Council's Assembly of Mathematical and Physical Sciences. The work of the Committee is supported by the Defense Advanced Research Projects Agency, the Directorate for Research Applications of the National Science Founda- tion, the U.S. Geological Survey, the U.S. Air Force Office of Scientific Research, the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Admin- istration, the Division of Earth Sciences of the National Science Foundation, the U.S. Nuclear Regulatory Commission, and the U.S. Energy Research and Development Administration. The Panel wishes to express its appreciation for the inter- est and support of these agencies. Valuable assistance was obtained from many individuals regarding specific details of the report. In particular, Jon Peterson, Director of the USGS Albuquerque Seismological Laboratory, provided information about network operations and support.
PANEL ON SEISMOGRAPH NETWORKS E. R. Engdahl, NOAA/University of Colorado, Chairman Shelton S. Alexander, The Pennsylvania State University Michael A. Chinnery, Lincoln Laboratory, Massachusetts Institute of Technology Adam Dziewonski, Harvard University J. Freeman Gilbert, University of California, San Diego at La Jolla Donald V. Helmberger, California Institute of Technology Bryan L. Isacks, Cornell University Liaison Members John R. Filson, Advanced Research Projects Agency Edward A. Flinn, National Aeronautics and Space Administration Robert M. Hamilton, U.S. Geological Survey Roy E. Hanson, National Science Foundation James F. Lander, National Oceanic and Atmospheric Administration Staff Joseph W. Berg, Jr., Executive Secretary Albert N. Bove, Staff Officer VII
COMMITTEE ON SEISMOLOGY J. Freeman Gilbert, University of California, San Diego at La Jolla, Chairman Lloyd S. Cluff, Woodward-Clyde Consultants E. R. Engdahl, NOAA/University of Colorado John I. Ewing, Woods Hole Oceanographic Institution William J. Hall, University of Illinois David D. Jackson, University of California at Los Angeles Lane R. Johnson, University of California at Berkeley Sidney Kaufman, Cornell University Carl Kisslinger, University of Colorado Robert P. Meyer, University of Wisconsin Otto W. Nuttli, St. Louis University C. H. Scholz, Lamont-Doherty Geological Observatory Don L. Anderson, California Institute of Technology, ex officio Liaison Members William J. Best, U.S. Air Force Office of Scientific Research Edward A. Flinn, National Aeronautics and Space Administration Robert M. Hamilton, U.S. Geological Survey Roy E. Hanson, National Science Foundation Jerry Harbour, U.S. Nuclear Regulatory Commission George A. Kolstad, U.S. Energy Research and Development Administration James F. Lander, National Oceanic and Atmospheric Administration Carl F. Romney, Advanced Research Projects Agency John B. Scalzi, National Science Foundation Vlll
Joseph W. Siry, National Aeronautics and Space Administration Robert E. Wallace, U.S. Geological Survey Staff Joseph W. Berg, Jr., Executive Secretary Albert N. Bove, Staff Officer IX
CONTENTS l Summary and Major Recommendations l 2 Introduction 5 3 Early History of Seismic Networks and Instrumentation 8 4 The Worldwide Standardized Seismograph Network ll Origin and Description, ll; Capabilities and Accomplishments, l3; Support, 20 5 New Developments and Capabilities 23 High-Gain Long-Period System, 24; Seismic Research Observatories, 24; Abbreviated Seismic Research Observatories, 27; Arrays, 27; Data Storage and Distribution, 3l; Interna- tional Deployment of Accelerometers, 32; Potential for Very-Long-Period Measurements, 33; Administration and Support of Networks, 34; The Need for Portable Instruments, 35; Space-Related Studies, 35; Ocean-Bottom Seismographs, 36; Calibration, 37; The Need for On-Scale Recording, 39 6 Improved Worldwide Standardized Seismograph Network 4l Description, 4l; Data Exchange, 44; Summary, 44 7 International Aspects 46
8 Data Handling, Processing, and User Services 49 Data Handling and Processing, 50; The Need for Regional Research Centers, 52; User Services, 54 9 Support for the Improved Worldwide Standardized Seismograph Network 56 Bibliography 6l Glossary 63 Appendix A. Research Directions 65 Appendix B. International Comment on the Worldwide Standardized Seismograph Network: Integrated Networks and User Services 74
