Anomalous seismic activity with wide-ranging behavior has been detected in the vicinity of the Mendocino Triple Junction (MTJ) and offshore transform faults. Among those unusual earthquakes are non-volcanic tremors, repeating earthquakes and slow-rupture or low-stress-drop earthquakes. These unusual events, together with 'typical' earthquakes, provide clues regarding the mechanics of faulting in the offshore region. One difficulty in the study of seismicity of the region is that the events located far offshore may go undetected or they may have poor locations with large uncertainty. Another difficulty is that there is a class of events that have either low stress drop or have slow rupture processes that make typical detection difficult. We present here preliminary results of a low-frequency continuous waveform scanning method to detect and locate events in the offshore region as well as compute the seismic moment tensor.

Berkeley Seismological Laboratory
215 McCone Hall, UC Berkeley, Berkeley, CA 94720-4760
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