Fault healing inferred from time dependent variations in source properties of repeating earthquakes

Chris Marone, John E. Vidale, William L. Ellsworth

Research output: Contribution to journalArticle

126 Scopus citations

Abstract

We analyze two sets of repeating earthquakes on the Calaveras fault to estimate in‐situ rates of fault strengthening (healing). Earthquake recurrence intervals tr range from 3 to 803 days. Variations in relative moment and duration are combined to study changes in stress drop, rupture dimension, rupture velocity, and particle velocity as a function of tr. Healing rates and source variations are compared with predictions of laboratory‐derived friction laws. Two interpretations of event duration τ are used: one in which τ is given by the ratio of slip to particle velocity and one in which it scales as rupture dimension divided by rupture velocity. Our data indicate that faults strengthen during the interseismic period. We infer that source dimension decreases with tr due to aseismic creep within the region surrounding the repeating events. Stress drop increases 1–3MPa per decade increase in tr, which represents an increase of a factor of 2–3 relative to events with tr between 10 and 100 days. This rate of fault healing is consistent with extrapolations of laboratory measurements of healing rates if fault strength is high, on order of 60MPa, and stress drop is roughly 10% of this value.

Original languageEnglish (US)
Pages (from-to)3095-3098
Number of pages4
JournalGeophysical Research Letters
Volume22
Issue number22
DOIs
StatePublished - Nov 15 1995

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Earth and Planetary Sciences(all)

Fingerprint Dive into the research topics of 'Fault healing inferred from time dependent variations in source properties of repeating earthquakes'. Together they form a unique fingerprint.

  • Cite this