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Seismic Monitoring Then (Loma Prieta) and Now. David Oppenheimer USGS – Menlo Park. Acknowledgements. CISN Institutions CA Geological Survey Caltech UC Berkeley USGS Menlo Park USGS Pasadena. People Technicians Communications specialists IT professionals Electrical engineers
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Seismic MonitoringThen (Loma Prieta) and Now David Oppenheimer USGS – Menlo Park
Acknowledgements • CISN Institutions • CA Geological Survey • Caltech • UC Berkeley • USGS Menlo Park • USGS Pasadena • People • Technicians • Communications specialists • IT professionals • Electrical engineers • Data analysts • Seismologists
How did we do in Loma Prieta? • NCSN computers not well secured • Generator auto-started • Networking went down • RTP and CUSP data recorded • Small amount of analog data lost several hours after quake • Initial location estimated from RTP picks on monitor. Hours until computed location available • No web, ShakeMap, FF, mechs, … • No public datacenter • No media • USGS-MP, UCB provide independent information
Significant Improvementsin Instrumentation • Then (1989) • 64 SM reference sites between Gilroy -Santa Rosa • 45 structures • No digital, low dynamic range • Today • 509 SM reference sites • 136 CGS, 24 NSMP buildings and lifeline structures • 23 boreholes (15 BP, 4 NC, 4 NP) • All 18-24 bit digital
UC Berkeley CA Geological Survey N CA Seismic Net NSMP
Infrastructure Today • All hardware secured • Generator power + UPS • Redundant machines • Waveform recording • Dataloggers • Microwave hubs • Tape • Waveservers • NCEDC • Resilient microwave
Near Real-time Products • Loma Prieta • Locations • Hypoinverse (NCSN) • Magnitudes • Md (5.5) – NCSN • Ml (7.0) - UCB • Today • Locations • Hypoinverse • Double Difference • Web - client side • Mags – md, ml, mw • Mechanisms - fm, mt • Finite fault • Directivity • Data (NCEDC) • ENS, Feeds, GE • ShakeMaps • Aftershock probabilities • Engineering SM reports
What’s Next? • Template event identification • Upgrades for 235 analog short-period stations (NC) • Better waveform Q/C • EEW • Cheaper hardware, telemetry = higher station density