Offshore Earthquake 2012 in the California Borderlands: Possible Extension of Seismically Active Area Offshore
Abstract
The California Borderlands is a tectonically active region with abundant seismic activity. In 2012, an earthquake epicenter was located on the eastern Pacific Plate west of the Patton Escarpment (31.08N, 119.61W). The earthquake was a magnitude 6.3 with a normal focal mechanism. In the past, seismic activity was thought not to extend past the Patton Escarpment. With this offshore earthquake, the extent of seismically active structures past the Patton Escarpment has been brought into question. On a recent Marine Geology and Geophysics Chief Scientists Training Cruise, early career scientists worked together to develop projects that could be completed aboard the RV Sikuliaq. A survey was completed of the earthquake area collecting gravity, multibeam, and sub-bottom profiler data. The survey was designed to identify seafloor morphology or internal structure that could have localized the unexpected offshore seismic activity. Possible mechanisms for the earthquake are a structure linked to the fault system with in the California Borderlands that was extinct but reactivated. Another possibility is that a structure in the oceanic lithosphere may have reactivated to accommodate movement. Establishing the possible mechanism of the 2012 earthquake can determine the possibility of other seismic activity offshore the Borderlands.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.T51G0557B
- Keywords:
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- 4315 Monitoring;
- forecasting;
- prediction;
- NATURAL HAZARDS;
- 7250 Transform faults;
- SEISMOLOGY;
- 8106 Continental margins: transform;
- TECTONOPHYSICS;
- 8118 Dynamics and mechanics of faulting;
- TECTONOPHYSICS