Long-term broadband seismic observatory in Monterey Bay
Project Manager/Lead Scientist: Debra Stakes
Lead Scientist: Barbara Romanowicz
Lead Engineer: Paul McGill
The Monterey Ocean-Bottom Broadband (MOBB) seismic station, located on the western side of the plate boundary, provides improved coverage of Northern California earthquakes and acts as a continental margin station to record seismic data from global events. The system includes a three-component, broadband seismometer system, installed in a hollow PVC caisson and buried under the seafloor with glass beads; a current meter; and a differential pressure gauge (DPG). A separate recording and battery package is placed 10 meters away in an anti-trawling device, custom-built at MBARI. A one-day dive is made every three months, to replace the battery, collect the recording package, and re-center the seismometers. The instruments have progressively settled on the seafloor, and the recentering adjustments are now minor.
MOBB is the only existing shallow water broadband station, and thus our results will be critical to characterizing this physical environment and addressing methodologies to extract the best data. The data are now broadly available through the Northern California Earthquake Data Center (NCEDC). The quality of the MOBB data is surprisingly good, but software problems have limited the data acquisition from the most recent deployments. Early in 2004 we plan to resolve the software problems.
The installation and support of this instrument, and its predecessor MOISE, have provided leadership for other observatory efforts. This deployment system has been emulated by JAMSTEC and is becoming the norm for the community. The MOBB RIN (remote instrument node) design was adopted for use in the Keck Experiment, and one system is already successfully collecting data on the Endeavour Segment.