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Sedimentation as a Control for Large Submarine Landslides: Mechanical Modeling and Analysis of the Santa Barbara Basin
Author(s) -
Stoecklin A.,
Friedli B.,
Puzrin A. M.
Publication year - 2017
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1002/2017jb014752
Subject(s) - landslide , geology , submarine landslide , structural basin , sedimentation , shearing (physics) , sedimentary rock , geomorphology , submarine , geotechnical engineering , seismology , geochemistry , sediment , oceanography
The volume of submarine landslides is a key controlling factor for their damage potential. Particularly large landslides are found in active sedimentary regions. However, the mechanism controlling their volume, and in particular their thickness, remains unclear. Here we present a mechanism that explains how rapid sedimentation can lead to localized slope failure at a preferential depth and set the conditions for the emergence of large‐scale slope‐parallel landslides. We account for the contractive shearing behavior of the sediments, which locally accelerates the development of overpressures in the pore fluid, even on very mild slopes. When applied to the Santa Barbara basin, the mechanism offers an explanation for the regional variation in landslide thickness and their sedimentation‐controlled recurrence. Although earthquakes are the most likely trigger for these mass movements, our results suggest that the sedimentation process controls the geometry of their source region. The mechanism introduced here is generally applicable and can provide initial conditions for subsequent landslide triggering, runout, and tsunami‐source analyses in sedimentary regions.