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Fault healing promotes high-frequency earthquakes in laboratory experiments and on natural faults

Nature

By:
, , , and
DOI: 10.1038/nature11512

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Abstract

Faults strengthen or heal with time in stationary contact and this healing may be an essential ingredient for the generation of earthquakes. In the laboratory, healing is thought to be the result of thermally activated mechanisms that weld together micrometre-sized asperity contacts on the fault surface, but the relationship between laboratory measures of fault healing and the seismically observable properties of earthquakes is at present not well defined. Here we report on laboratory experiments and seismological observations that show how the spectral properties of earthquakes vary as a function of fault healing time. In the laboratory, we find that increased healing causes a disproportionately large amount of high-frequency seismic radiation to be produced during fault rupture. We observe a similar connection between earthquake spectra and recurrence time for repeating earthquake sequences on natural faults. Healing rates depend on pressure, temperature and mineralogy, so the connection between seismicity and healing may help to explain recent observations of large megathrust earthquakes which indicate that energetic, high-frequency seismic radiation originates from locations that are distinct from the geodetically inferred locations of large-amplitude fault slip

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Fault healing promotes high-frequency earthquakes in laboratory experiments and on natural faults
Series title:
Nature
DOI:
10.1038/nature11512
Volume
491
Year Published:
2012
Language:
English
Publisher:
Nature Publishing Group
Contributing office(s):
Earthquake Science Center
Description:
5 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Nature
First page:
101
Last page:
104