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Regional tectonic stress near the San Andreas fault in central and southern California

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journal contribution
posted on 09.02.2021, 19:14 by John Townend, M Zoback
Throughout central and southern California, a uniform NNE-SSW direction of maximum horizontal compressive stress is observed that is remarkably consistent with the superposition of stresses arising from lateral variations in lithospheric buoyancy in the western United States, and farfield Pacific-North America plate interaction. In central California, the axis of maximum horizontal compressive stress lies at a high angle to the San Andreas fault (SAF). Despite relatively few observations near (±10 km) the fault, observations in the greater San Francisco Bay area indicate an angle of as much as 85°, implying extremely low fault strength. In southern California, observations of stress orientations near the SAF are rotated slightly counter-clockwise with respect to the regional field. Nevertheless, we observe an approximately constant angle between the SAF and the maximum horizontal stress direction of 68 ± 7° along ∼400 km of the fault, indicating that the SAF has moderately low frictional strength in southern California. Copyright 2004 by the American Geophysical Union.

History

Preferred citation

Townend, J. & Zoback, M. (2004). Regional tectonic stress near the San Andreas fault in central and southern California. Geophysical Research Letters, 31(15, L15S11), 1-5. https://doi.org/10.1029/2003GL018918

Journal title

Geophysical Research Letters

Volume

31

Issue

15, L15S11

Publication date

01/01/2004

Pagination

1-5

Publisher

American Geophysical Union (AGU)

Publication status

Published

Contribution type

Article

ISSN

0094-8276

eISSN

1944-8007

Article number

L15S11

Language

en