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Interseismic Velocity Field and Seismic Moment Release in Northern Baja California, Mexico

Jose Javier Gonzàlez-Garcìa, Alejandro Gonzalez-Ortega, & David T. Sandwell

Published February 14, 2018, SCEC Contribution #8242

We have analyzed all available continuous Global Positioning System (cGPS) and campaign-mode GPS data from northern Baja California, Mexico, covering the 1993.1–2010.1 period to obtain a consistent interseismic velocity field to derive a con- tinuous strain-rate field. The analysis shows concentrations of high strain rate along the Imperial/Cerro Prieto fault system extending from the Salton Sea to the Gulf of California, with strike-slip faulting consistent with principal strain axes direction within the area of largest historical and instrumental seismic re- lease. We translated the strain rate into geodetic moment accu- mulation rate to evaluate the potential of seismic activity of the region and compare with the actual seismic release of his- torical and instrumental earthquake catalog. Comparison of regional moment accumulation rate based on geodesy (M_ g0 6:3 1:3 × 1018 N · m=yr) to the corresponding moment re- lease rate by earthquakes (M_ s0 2:7 0:8 × 1018 N · m=yr) highlights a moment rate deficit equivalent to an Mw 7.5–7.8 earthquake. As part of this accumulated moment was released by the recent 2010 Mw 7.2 El Mayor–Cucapah earthquake, these results can provide input constraints on earthquake forecasts for the northern Baja California fault system.

Gonzàlez-Garcìa, J., Gonzalez-Ortega, A., & Sandwell, D. T. (2018). Interseismic Velocity Field and Seismic Moment Release in Northern Baja California, Mexico. Seismological Research Letters, 89(2A), 526-533. doi: 10.1785/0220170133.