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Humboldt slide - A large shear-dominated retrogressive slope failure

Marine Geology

By:
, , and
DOI: 10.1016/S0025-3227(98)00121-2

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Abstract

Humboldt Slide is a large, complex slide zone located on the northern California continental margin. Its three-dimensional architecture has been imaged by a combination of multibeam bathymetry, Huntec Deep-Tow seismic profiling, and sidescan sonar. The slide is interpreted to be Late Pleistocene to early Holocene in age and was caused by a combination of factors. The area of the slide is a local depocenter with high accumulation rates of organic-rich sediment; there has been local steepening of slopes by tectonic uplifts; and the entire area is one of high seismicity. Overall, the failure occurred by retrogressive, shear-dominated, minimum movement apparently as a sequence of events. Failure initially occurred by subsidence extension at the middle of the feature, followed by upslope retrogressive failure and downslope compression, and finally by translational sliding at the top of the slide. Degassing, as evidenced by abundant pockmarks, may have inhibited downslope translation. The slide may still be active, as suggested by offsets in Holocene hemipelagic sediment draped over some of the shear surfaces. Crown cracks occur above the present head of the failure and may represent the next generation of failure.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Humboldt slide - A large shear-dominated retrogressive slope failure
Series title:
Marine Geology
DOI:
10.1016/S0025-3227(98)00121-2
Volume
154
Issue:
1-4
Year Published:
1999
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Marine Geology
First page:
323
Last page:
338
Number of Pages:
16