HR: 14:30h
AN: S33C-03    [Abstracts]
TI: The Berkeley Digital Seismic Network
AU: Romanowicz, B
EM: barbara@seismo.berkeley.edu
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AU: Dreger, D
EM: dreger@seismo.berkeley.edu
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AU: Neuhauser, D
EM: doug@seismo.berkeley.edu
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AU: Karavas, W
EM: karavas@seismo.berkeley.edu
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AU: * Hellweg, M
EM: peggy@seismo.berkeley.edu
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AU: Uhrhammer, R
EM: bob
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AU: Lombard, P
EM: lombard
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AU: Friday, J
EM: john
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AU: Lellinger, R
EM: rickl
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AU: Gardner, J
EM: jarrett
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AU: McKenzie, M R
EM: rick
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AU: Bresloff, C
EM: cyndyb
AF: Berkeley Seismological Laboratory, UC Berkeley 215 McCone Hall #4760, Berkeley, CA 94720, United States
AB: Since it began monitoring earthquakes in northern California 120 years ago, the Berkeley Seismological Laboratory (BSL) has been striving to produce the highest quality and most complete seismic data possible in the most modern way. This goal has influenced choices in instrumentation, installation and telemetry, as well as the investment in expertise and manpower. Since the transition to broadband (BB) instrumentation in the mid- 1980s and to a fully digitally telemetered network in the early 1990s, we have continued these efforts. Each of our 25 BB installations includes three component BB seismometers (STS-1s or STS-2) and digital accelerometers to capture the full range of ground motion from distant teleseisms to large, nearby earthquakes (almost 250 dB). The ground motion is recorded on-site by 24 bit dataloggers. Additional environmental parameters, such as temperature and pressure, are also monitored continuously. Many stations record also C-GPS data that is transmitted continuously to the BSL via shared real-time telemetry. The BDSN's first stations were installed in abandoned mines. In the last 15 years, we developed installations using buried shipping containers to reduce environmental noise and provide security and easy access to the equipment. Data are transmitted in real-time at several sampling rates to one or more processing centers, using frame relay, radio, microwave, and/or satellite. Each site has 7-30 days of onsite data storage to guard against data loss during telemetry outages. Each station is supplied with backup batteries to provide power for 3 days. The BDSN real-time data acquisition, earthquake analysis and archiving computers are housed in a building built to "emergency grade" seismic standards, with air conditioning and power backed up by a UPS and a large generator. Data latency and power are monitored by automated processes that alert staff via pager and email. Data completeness and timing quality are automatically assessed on a daily basis for all stations, and the results are reviewed using the program calqc. Missing data are semi-automatically retrieved from the stations and merged into the data streams, while timing corrections are made manually. Calqc also controls the final transfer of the data to the archive. We assess waveforms from all BDSN components using several tools, such as daily noise spectra. BDSN waveforms are available immediately after they arrive at the data center through the DART (Data Available in Real Time), while archived data can be retrieved from the Northern California Earthquake Data Center. The BDSN contributes data to the joint USGS/UC Berkeley earthquake notification program for northern California, which produces, automatically and in quasi-real- time, earthquake locations and size as well as other source parameters. In particular, three component broadband data from the BDSN are essential for the automatic and rapid determination of Ml, and since 1994, Mw and moment tensors for events with Mw>4. Since 2003, finite source models are calculated for events with Mw>6. The BDSN is part of the California Integrated Seismic Network and contributes data for the determination of ShakeMaps in that framework.
UR: http:seismo.berkeley.edu
DE: 7200 SEISMOLOGY
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
DE: 7294 Seismic instruments and networks (0935, 3025)
DE: 7299 General or miscellaneous
SC: Seismology [S]
MN: 2007 Joint Assembly