Seismic and aseismic moment budget and implication for the seismic potential of the parkfield segment of the san andreas fault

Sylvain Michel, Jean Philippe Avouac, Romain Jolivet, Lifeng Wang

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

This study explores methods to assess the seismic potential of a fault based on geodetic measurements, geological information of fault-slip rate, and seismicity data. The methods are applied to the Parkfield section along the San Andreas fault (SAF) at the transition zone between the SAF creeping segment in the north and the locked section of Cholame to the south, where Mw ∼ 6 earthquakes occurred every 24.5 yrs on average since the 1857 Mw 7.7 Fort Tejon earthquake. We compare the moment released by the known earthquakes and associated postseismic deformation with the moment deficit accumulated during the interseismic period derived from geodetic measurement of interseismic strain. We find that the recurring Mw 6 earthquakes are insufficient to balance the slip budget. We discuss and evaluate various possible scenarios which might account for the residual moment deficit and implications of the possible magnitude and return period of Mw >6 earthquakes on that fault segment. The most likely explanation is that this fault segment hosts Mw 6.5–7.5 earthquakes, with a return period of 140–300 yrs. Such events could happen as independent earthquakes in conjunction with ruptures of the Carrizo plain segment of the SAF. We show how the results from our analysis can be formally incorporated in probabilistic seismic hazard assessment assuming various magnitude–frequency distribution and renewal time models.

Original languageEnglish
Pages (from-to)19-38
Number of pages20
JournalBulletin of the Seismological Society of America
Volume108
Issue number1
DOIs
Publication statusPublished - Feb 2018

Fingerprint Dive into the research topics of 'Seismic and aseismic moment budget and implication for the seismic potential of the parkfield segment of the san andreas fault'. Together they form a unique fingerprint.

  • Cite this