Triggering mechanism and tsunamogenic potential of the Cape Fear Slide complex, U.S. Atlantic margin

Geochemistry, Geophysics, Geosystems
By: , and 

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Abstract

Analysis of new multibeam bathymetry data and seismic Chirp data acquired over the Cape Fear Slide complex on the U.S. Atlantic margin suggests that at least 5 major submarine slides have likely occurred there within the past 30,000 years, indicating that repetitive, large-scale mass wasting and associated tsunamis may be more common in this area than previously believed. Gas hydrate deposits and associated free gas as well as salt tectonics have been implicated in previous studies as triggers for the major Cape Fear slide events. Analysis of the interaction of the gas hydrate phase boundary and the various generations of slides indicates that only the most landward slide likely intersected the phase boundary and inferred high gas pressures below it. For much of the region, we believe that displacement along a newly recognized normal fault led to upward migration of salt, oversteepening of slopes, and repeated slope failures. Using new constraints on slide morphology, we develop the first tsunami model for the Cape Fear Slide complex. Our results indicate that if the most seaward Cape Fear slide event occurred today, it could produce waves in excess of 2 m at the present-day 100 m bathymetric contour.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Triggering mechanism and tsunamogenic potential of the Cape Fear Slide complex, U.S. Atlantic margin
Series title Geochemistry, Geophysics, Geosystems
DOI 10.1029/2007GC001722
Volume 8
Issue 12
Year Published 2007
Language English
Publisher Wiley
Contributing office(s) Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center
Description 16 p.
Country United States
Other Geospatial Cape Fear Slide