DWR/O&M Earthquake Engineering Section FY2006 Update James D. Agnew, M.S. Senior Seismologist 17 Nov 2005

Program began in early 1960s Older than CGS/SMIP, but a smaller program 1) Real-time monitoring for SWP (M>=3.7) 2) DWR Strong Motion Program 1963 – Oroville Dam (seismicity of area around dam prior to construction) 1964 – Orestimba Creek Siphon; Buena Vista PP; 1966 – Oso PP Expanded slowly to present status as limited funding became available

FY2006 status 104 Strong Motion sensor sites 22 Weak Motion sensor sites (used for magnitude and epicenter determination) 345 channels of seismic data, 80 real-time Installing 3 new strong motion instruments this week at Perris Dam/Reservoir Only weak motion sites are used for event detection, location & Magnitude

Current Challenges Uneven distribution of instruments Archaic analog instruments at some sites Numerous gaps in coverage Lack of communication with instruments Phone lines can be very noisy, unreliable Severe lack of funding for upgrades (until now?); Little to no spare equipment

Plans for FY Replace old 11-bit 1g digital SM instru- ments with new 18-bit 4g digital ones Add field digitizers to analog instruments to eliminate noise problems Add more two-way communication with instruments to eliminate field visits Institute new event-recognition software Purchase spare parts & sensors

Plans for FY (cont’d) Share more data with CISN partners Contribute strong motion data to SHAKEMAP production & NGA effort Find a new site for old seismic records Update our web pages Investigate VSAT communication/costs to eliminate phone line problems Initiate a Station/Event database

Costs (tentative) Around $500k to replace old equipment and digitize analog data Up to $700k if spare accelerometers can be purchased, and/or new sites added Up to $875k if some stations get VSAT Savings – less fieldwork, per diem, eliminate phone line costs with VSAT, increased speed/accuracy of reporting