Undrained Sediment Loading Key to Long-Runout Submarine Mass Movements: Evidence from the Caribbean Volcanic Arc

Barry Voight, Anne Le Friant, Georges Boudon, Christine Deplus, Jean-Christophe Komorowski, Elodie Lebas, R. Stephen J. Sparks, Peter Talling, Jess Trofimovs

Research output: Chapter in Book/Report/Conference proceedingConference Contribution (Conference Proceeding)

7 Citations (Scopus)

Abstract

Long undersea debris runout can be facilitated by a boundary layer formed by weak marine sediments under a moving slide mass. Undrained loading of such offshore sediment results in a profound drop of basal shear resistance, compared to subaerial shear resistance, enabling long undersea runout. Thus large longrunout submarine landslides are not truly enigmatic (Voight and Elsworth 1992, 1997), but are understandable in terms of conventional geotechnical principles. A corollary is that remoulded undrained strength, and not friction angle, should be used for basal resistance in numerical simulations. This hypothesis is testable via drilling and examining the structure at the soles of undersea debris avalanches for indications of incorporation of sheared marine sediments, by tests of soil properties, and by simulations. Such considerations of emplacement process are an aim of ongoing research in the Lesser Antilles (Caribbean Sea), where multiple offshore debris avalanche and dome-collapse debris deposits have been identified since 1999 on swath bathymetric surveys collected in five oceanographic cruises. This paper reviews the prehistoric and historic collapses that have occurred offshore of Antilles arc islands and summarizes ongoing research on emplacement processes.

Original languageEnglish
Title of host publicationSUBMARINE MASS MOVEMENTS AND THEIR CONSEQUENCES
EditorsY Yamada, K Kawamura, K Ikehara, Y Ogawa, R Urgeles, D Mosher, J Chaytor, M Strasser
Place of PublicationDORDRECHT
PublisherSpringer
Pages417-428
Number of pages12
ISBN (Print)978-94-007-2161-6
DOIs
Publication statusPublished - 2012
Event5th International Symposium on Submarine Mass Movements and Their Consequences - Kyoto, Japan
Duration: 24 Oct 201126 Oct 2011

Conference

Conference5th International Symposium on Submarine Mass Movements and Their Consequences
CountryJapan
CityKyoto
Period24/10/1126/10/11

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