Rupture history of 2014 Mw 6.0 South Napa earthquake inferred from near-fault strong motion data and its impact to the practice of ground strong motion prediction
Cedric Twardzik, Ralph J. Archuleta, & Chen JiPublished April 14, 2015, SCEC Contribution #6108
The spatiotemporal rupture history of the 2014 South Napa earthquake is constrained using near-fault strong motion records. An aggressive source parameterization with 1372 subfaults is adopted to match the signals in the transverse components up to 4 Hz. The result reveals that the rupture of the Napa earthquake initiated at a depth of 9.84 km and propagated mainly to north-northwest (NNW) and updip on a 13 km long fault patch. A gradual increase in average rise time when the rupture propagates to shallower depth is observed. However, it is the rupture of a small (Mw 4.9), isolated, and high stress drop fault patch that excited the largest ground acceleration at stations south of the epicenter. Such fine-scale rupture heterogeneity shall be considered during seismic hazard analysis.
Key Words
2014 South Napa earthquake, aggressive source parameterization, 4 Hz seismic signals, variation of rise time, seismic hazard analysis
Citation
Twardzik, C., Archuleta, R. J., & Ji, C. (2015). Rupture history of 2014 Mw 6.0 South Napa earthquake inferred from near-fault strong motion data and its impact to the practice of ground strong motion prediction . Geophysical Research Letters, 42(7), 2149-2156. doi: 10.1002/2015GL063335. http://onlinelibrary.wiley.com/doi/10.1002/2015GL063335/full
