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Design Concepts for a Global Telemetered Seismograph Network

Open-File Report 82-703

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Abstract

INTRODUCTION This study represents a first step in developing an integrated, real-tlme global seismic data acquisition system -- a Global Telemetered Seismograph Network (GTSN). The principal objective of the GTSN will be to acquire reliable, high-quality, real-time seismic data for rapid location and analysis of seismic events. A secondary, but important, objective of the GTSN is to augment the existing off-line seismic data base available for research. The deployment of the GTSN will involve a variety of interrelated activities -- development of the data acquisition and receiving equipment, establishment of satellite and terrestrial communication links, site selection and preparation, training of station personnel, equipment installation, and establishment of support facilities. It is a complex program and the develop- ment of a sound management plan will be essential. The purpose of this study is not to fix design goals or dictate avenues of approach but to develop work- ing concepts that may be used as a framework for program planning. The international exchange of seismic data has been an important factor in the progress that has been made during the past two decades in our under- standing of earthquakes and global tectonics. The seismic data base available for analysis and research is derived principally from the Global Seismograph Network (GSN), which is funded and managed by the U.S. Geological Survey (USGS). The GSN comprises some 120 seismograph stations located in more than 60 countries of the world. Established during the 1960's with the installation of the World-Wide Standardized Seismograph Network (WWSSN), the GSN has been augmented in recent years by the installation of more advanced data systems, such as the Seismic Research Observatories (SRO), the modified High-Gain Long- Period (ASRO) seismographs, and the digital WWSSN (DWWSSN). The SRO, ASRO, and DWWSSN stations have the common, distinctive feature of digital data recording, so they are known collectively as the Global Digital Seismograph Network (GDSN). The fundamental objective in operating the GSN is to create and update a seismic data base that is accessible without restrictions to organizations and research scientists throughout the world. The USGS provides cooperating stations with instrumentation, training, and continuing support, including supplies and on-site maintenance. In return, the host organization operates the equipment and sends the recorded data to the USGS. Analog data (seismo- grams) are microfilmed and about four million copies are requested annually by researchers. Digital data, which are recorded on magnetic tape, are organized by the USGS Albuquerque Seismological Laboratory (ASL) into network- day tapes and copies of the day tapes are furnished to data users through national and regional data centers. After copying, original data are returned to the stations and used for local research. Most of the stations in the GSN also provide the USGS with seismic readings -- phase arrival times and amplitudes scaled from the seismograms. These readings are transmitted on a daily or biweekly basis via commercial or diplomatic communication channels. They are used by the USGS National Earthquake Information Service (NEIS) to determine the location and magnitude of earthquakes occurring throughout the world. The results are published monthly in bulletins that are distributed to the participating stations and virtually all scientific organizations that are involved in seismological studies. It is a much-valued service that provides a current, updated catalog of seismic activity on a global scale. The NEIS also has the responsibility for rapid reporting of large and potentially destructive earthquakes. The NEIS issues news bulletins as soon as possible after the occurrence of magnitude 6.5 or greater earthquakes (magnitude 5 or greater in the conterminous Un

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Design Concepts for a Global Telemetered Seismograph Network
Series title:
Open-File Report
Series number:
82-703
Edition:
-
Year Published:
1982
Language:
ENGLISH
Publisher:
Geological Survey (U.S.)
Contributing office(s):
Albuquerque Seismological Laboratory
Description:
40 p.