Shallow geometry and displacements on the San Andreas Fault near Point Arena based on trenching and 3-D georadar surveying

Details

Serval ID
serval:BIB_26C0EC7897A9
Type
Article: article from journal or magazin.
Collection
Publications
Title
Shallow geometry and displacements on the San Andreas Fault near Point Arena based on trenching and 3-D georadar surveying
Journal
Geophysical Research Letters
Author(s)
Gross R., Green A., Holliger K., Horstmeyer H., Baldwin J.
ISSN-L
0094-8276
Publication state
Published
Issued date
2002
Peer-reviewed
Oui
Volume
29
Pages
1973
Language
english
Abstract
To characterize buried portions of the San Andreas Fault (SAF) near
its northern extremity in California, three trenches were excavated
perpendicular to it and a 3-D georadar data set was acquired. Similar
sequences of unconsolidated fluvial sediments, Franciscan serpentinite
and active fault zones were observed in the three trenches. Fault
traces in the trenches were initially assumed to be part of a single
SAF strand. However, the georadar data demonstrated the existence
of two SAF strands, one of which was exposed in the central and southern
trenches and the other in the northern trench. Offset of a linear-trending
georadar feature (possibly a fluvial paleochannel) suggests that
4.5-5.5 m of horizontal displacement occurred across the eastern
SAF strand, either during the 1906 San Francisco earthquake or earlier.
Georadar reflections from flat-lying and trough-shaped sedimentary
boundaries are vertically offset by 0.2-0.3 m along both fault strands.
Create date
25/11/2013 18:27
Last modification date
20/08/2019 13:05
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