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Using high-resolution multibeam bathymetry to identify seafloor surface rupture along the Palos Verdes fault complex in offshore Southern California

Geology

By:
, ,
DOI: 10.1130/0091-7613(2000)28<587:UHMBTI>2.0.CO;2

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Abstract

Recently acquired high-resolution multibeam bathymetric data reveal several linear traces that are the surficial expressions of seafloor rupture of Holocene faults on the upper continental slope southeast of the Palos Verdes Peninsula. High-resolution multichannel and boomer seismic-reflection profiles show that these linear ruptures are the surficial expressions of Holocene faults with vertical to steep dips. The most prominent fault on the multibeam bathymetry is about 10 km to the west of the mapped trace of the Palos Verdes fault and extends for at least 14 km between the shelf edge and the base of the continental slope. This fault is informally called the Avalon Knoll fault for the nearby geographic feature of that name. Seismic-reflection profiles show that the Avalon Knoll fault is part of a northwest-trending complex of faults and anticlinal uplifts that are evident as scarps and bathymetric highs on the multibeam bathymetry. This fault complex may extend onshore and contribute to the missing balance of Quaternary uplift determined for the Palos Verdes Hills and not accounted for by vertical uplift along the onshore Palos Verdes fault. We investigate the extent of the newly located offshore Avalon Knoll fault and use this mapped fault length to estimate likely minimum magnitudes for events along this fault.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Using high-resolution multibeam bathymetry to identify seafloor surface rupture along the Palos Verdes fault complex in offshore Southern California
Series title:
Geology
DOI:
10.1130/0091-7613(2000)28<587:UHMBTI>2.0.CO;2
Volume
28
Issue:
7
Year Published:
2000
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
587
Last page:
590
Number of Pages:
4