Time-dependent model of creep on the Hayward fault from joint inversion of 18 years of InSAR and surface creep data

Manoochehr Shirzaei, R. Bürgmann

Research output: Contribution to journalArticlepeer-review

54 Scopus citations

Abstract

Spatial and temporal variations of aseismic fault creep influence the size and timing of large earthquakes along partially coupled faults. To solve for a time-dependent model of creep on the Hayward fault, we invert 18 years of surface deformation data (1992-2010), obtained by interferometric processing of 52 and 50 SAR images acquired by the ERS1/2 and Envisat satellites, respectively, and surface creep data obtained at 19 alinement and 4 creepmeter stations. For multi-temporal analysis of the SAR data we developed a method for identifying stable pixels using wavelet multi-resolution analysis. We also implement a variety of wavelet-based filters for reducing the effects of environmental artifacts. Using a reweighted least squares approach, we inverted the interferometric data to generate a time series of surface deformation over the San Francisco Bay Area with a precision of better than a few millimeters. To jointly invert the InSAR displacement time series and the surface creep data for a time-dependent model of fault creep, we use a robust inversion approach combined with a Kalman filter. The time-dependent model constrains a zone of high slip deficit that may represent the locked rupture asperity of past and future M≈7 earthquakes. We identify several additional temporal variations in creep rate along the Hayward fault, the most important one being a zone of accelerating slip just northwest of the major locked zone. We estimate that a slip-rate deficit equivalent to Mw 6.3-6.8 has accumulated on the fault, since the last event in 1868.

Original languageEnglish (US)
Pages (from-to)1733-1746
Number of pages14
JournalJournal of Geophysical Research: Solid Earth
Volume118
Issue number4
DOIs
StatePublished - Apr 1 2013

Keywords

  • Hayward
  • InSAR
  • Time-dependent creep
  • inverse modeling

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'Time-dependent model of creep on the Hayward fault from joint inversion of 18 years of InSAR and surface creep data'. Together they form a unique fingerprint.

Cite this