02536nas a2200445   4500000000100000008004100001260003600042653003600078100001700114700001600131700001900147700002100166700003100187700001700218700001900235700001800254700001900272700002000291700002200311700001600333700001700349700001800366700001700384700001800401700002100419700002000440700002200460700001600482700001700498700001800515700001700533700001800550700002100568245011700589856005100706300001200757490000700769520129200776020002202068       2012                            d  bSpringer NetherlandsaDordrecht10aEarth and Environmental Science1 aBarry Voight1 aAnne Friant1 aGeorges Boudon1 aChristine Deplus1 aJean-Christophe Komorowski1 aElodie Lebas1 aStephen Sparks1 aPeter Talling1 aJess Trofimovs1 aYasuhiro Yamada1 aKiichiro Kawamura1 aKen Ikehara1 aYujiro Ogawa1 aRoger Urgeles1 aDavid Mosher1 aJason Chaytor1 aMichael Strasser1 aYasuhiro Yamada1 aKiichiro Kawamura1 aKen Ikehara1 aYujiro Ogawa1 aRoger Urgeles1 aDavid Mosher1 aJason Chaytor1 aMichael Strasser00aUndrained Sediment Loading Key to Long-Runout Submarine Mass Movements: Evidence from the Caribbean Volcanic Arc  uhttp://dx.doi.org/10.1007/978-94-007-2162-3_37  a417-4280 v313 aLong 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 long-runout 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.  a978-94-007-2162-3