HR: 1350h
AN: U23C-1448    [Abstracts]
TI: 50 years of Global Seismic Observations
AU: * Anderson, K R
EM: kent@iris.edu
AF: Incorporated Research Institutions for Seismology, 1200 New York Ave NW, Suite 800, Washington, DC 20005, United States
AU: Butler, R
EM: rhett@iris.edu
AF: Incorporated Research Institutions for Seismology, 1200 New York Ave NW, Suite 800, Washington, DC 20005, United States
AU: Berger, J
EM: jberger@ucsd.edu
AF: Institute of Geophysics and Planetary Physics, University of California, San Diego, 905 Gilman Drive, La Jolla, CA 92093, United States
AU: Davis, P
EM: pdavis@ucsd.edu
AF: Institute of Geophysics and Planetary Physics, University of California, San Diego, 905 Gilman Drive, La Jolla, CA 92093, United States
AU: Derr, J
EM: derr@usgs.gov
AF: USGS Albuquerque Seismological Laboratory, PO Box 82010, Albuquerque, NM 87198, United States
AU: Gee, L
EM: lgee@usgs.gov
AF: USGS Albuquerque Seismological Laboratory, PO Box 82010, Albuquerque, NM 87198, United States
AU: Hutt, C R
EM: bhutt@usgs.gov
AF: USGS Albuquerque Seismological Laboratory, PO Box 82010, Albuquerque, NM 87198, United States
AU: Leith, W S
EM: wleith@usgs.gov
AF: United States Geological Survey, 905 National Center, Reston, VA 20192, United States
AU: Park, J J
EM: jeffrey.park@yale.edu
AF: Geology and Geophysics Department, Yale University, P.O. Box 208109, New Haven, CT 06520, United States
AB: Seismological recordings have been made on Earth for hundreds of years in some form or another, however, global monitoring of earthquakes only began in the 1890's when John Milne created 40 seismic observatories to measure the waves from these events. Shortly after the International Geophysical Year (IGY), a concerted effort was made to establish and maintain a more modern standardized seismic network on the global scale. In the early 1960's, the World-Wide Standardized Seismograph Network (WWSSN) was established through funding from the Advanced Research Projects Agency (ARPA) and was installed and maintained by the USGS's Albuquerque Seismological Laboratory (then a part of the US Coast and Geodetic Survey). This network of identical seismic instruments consisted of 120 stations in 60 countries. Although the network was motivated by nuclear test monitoring, the WWSSN facilitated numerous advances in observational seismology. From the IGY to the present, the network has been upgraded (High-Gain Long-Period Seismograph Network, Seismic Research Observatories, Digital WWSSN, Global Telemetered Seismograph Network, etc.) and expanded (International Deployment of Accelerometers, US National Seismic Network, China Digital Seismograph Network, Joint Seismic Project, etc.), bringing the modern day Global Seismographic Network (GSN) to a current state of approximately 150 stations. The GSN consists of state-of-the-art very broadband seismic transducers, continuous power and communications, and ancillary sensors including geodetic, geomagnetic, microbarographic, meteorological and other related instrumentation. Beyond the GSN, the system of global network observatories includes contributions from other international partners (e.g., GEOSCOPE, GEOFON, MEDNET, F-Net, CTBTO), forming an even larger backbone of permanent seismological observatories as a part of the International Federation of Digital Seismograph Networks. 50 years of seismic network operations have provided valuable data for earth science research. Developments in communications and other technological advances have expanded the role of the GSN in rapid earthquake analysis, tsunami warning, and nuclear test monitoring. With such long-term observations, scientists are now getting a glimpse of Earth structure changes on human time scales, such as the rotation of the inner core, as well as views into climate processes. Continued observations for the next 50 years will enhance our image of the Earth and its processes.
UR: http://www.iris.edu/about/GSN
DE: 7294 Seismic instruments and networks (0935, 3025)
SC: Union [U]
MN: 2007 Fall Meeting