Journalartikel

Jahr der Veröffentlichung: 1997

Seiten: 24619-24626

Zeitschrift: Journal of Geophysical Research (JGR): Solid Earth

Bandnummer: 102

Heftnummer: B11

ISSN: 2169-9313

eISSN: 2169-9356

Open Access Status: Bronze

DOI Link: https://doi.org/10.1029/97JB01509

Verlag: American Geophysical Union

Abstract: 
Low frictional strength of faults is estimated based on existing models for earthquake recurrence, which account for compaction and hydrothermal lithification of fault rocks, as well as for the buildup of high fluid pressures in faults during interseismic periods. In areas of elevated heat flow and for a geothermal gradient of 30 degrees C/km, fault compaction, lithification, and changes in fluid pressure gradient are inferred to occur at shallow crustal depth (3 to 7 km). Calculated shearing resistance of faults at seismogenic depths is compatible with shear stress drops ascribed to moderate and large earthquakes. The high frequency of microearthquakes, as well as the occurrence of some larger mainshock hypocenters at shallow crustal depth along several strands of the San Andreas Fault system are consistent with a predicted minimum of crustal strength at the top of a high fluid pressure regime. On the basis of field evidence from many exhumed faults for lithification of fault gouge and for faulting at near-lithostatic fluid pressures, a modified crustal strength profile is suggested to represent the strength of many active faults which involve hydrothermal fluid flow.

Harvard-Zitierstil: Streit, J. (1997) Low frictional strength of upper crustal faults: A model, Journal of Geophysical Research: Solid Earth, 102(B11), pp. 24619-24626. https://doi.org/10.1029/97JB01509

APA-Zitierstil: Streit, J. (1997). Low frictional strength of upper crustal faults: A model. Journal of Geophysical Research: Solid Earth. 102(B11), 24619-24626. https://doi.org/10.1029/97JB01509