Submarine mass wasting off Southern Central Chile (Part 2): Pleistocene super-scale failures offshore Arauco Peninsula.

Geersen, Jacob, Völker, David, Behrmann, Jan Hinrich, Reichert, Christian and Krastel-Gudegast, Sebastian (2010) Submarine mass wasting off Southern Central Chile (Part 2): Pleistocene super-scale failures offshore Arauco Peninsula. [Talk] In: SFB 574 Subduction Workshop. , 04.- 07.11. 2010, Pucón, Chile .

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Abstract

Three Pleistocene super-scale slope failures are observed in high resolution bathymetric and reflection seismic data off Southern Chile, spanning the full width of the continental slope from the shelf break to the trench. With
mobilized volumes between 356 km$ and 460 km$, these slides range among the largest submarine landslides ever documented at active continental margins. Deposits of the individual slides are imaged as chaotic sequences in
reflection seismic lines buried beneath undisturbed turbiditic sediments in the Chile Trench. The ages of the three slides are about 0.26 Ma, 0.46 Ma and >0.57 – 0.78 Ma. The main preconditioning factor for the slope instabilities seems to be the uplift of the continental slope that results in peculiarly high slope angles, locally exceeding 40°. Uplift of the marine and continental
forearc of the study area is interpreted as the result of shortening across upper plate faults caused by the northward motion of the Chiloe Microplate and its collision with the South American Plate. As uplift of the marine and
continental forearc in this region is a long-term continuous process, observed slope instabilities are interpreted as a reiterate process and will happen again.
Though the consequences of such a failure would be catastrophic, the risk is for a major failure in the near future is small.

Document Type: Conference or Workshop Item (Talk)
Keywords: Geodynamics
Research affiliation: OceanRep > GEOMAR
OceanRep > SFB 574 > A1
OceanRep > SFB 574
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-GDY Marine Geodynamics
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-JRG-B4 Submarine Hazards
Date Deposited: 24 Nov 2010 08:01
Last Modified: 23 Feb 2012 05:05
URI: http://oceanrep.geomar.de/id/eprint/10109

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