TY - CHAP
T1 - Submarine Landslides Around Volcanic Islands
T2 - A Review of What Can Be Learned From the Lesser Antilles Arc
AU - IODP 340 Expedition Science Party
AU - Friant, Anne Le
AU - Lebas, Elodie
AU - Brunet, Morgane
AU - Lafuerza, Sara
AU - Hornbach, Matt
AU - Coussens, Maya
AU - Watt, Sebastian
AU - Cassidy, Michael
AU - Talling, Peter J.
N1 - We thank the drillers for their relentless efforts to drill through such difficult volcaniclastic material and all R/V JOIDES Resolution staff for their collaboration and efficient work on board. We are very grateful to C. Mével who encouraged and helped us to build our drilling proposal. We thank INSU, NERC, ANR‐13‐BS06‐0009, Labex UnivEarthS, FEDER INTERREG Caraibes program, JSPS, and NSF for funding analyses and IPGP for funding postdocs and PhD. We thank the staff of the Montserrat Volcano Observatory and the Martinique and Guadeloupe Volcanological and Seismological Observatory for assistance during the cruise and outreach education activities. Data from the IODP Expedition 340 can be obtained through the expedition’s implementing organization USIO (http://iodp.tamu.edu/ database) (IPGP contribution 3960).
PY - 2019/11/4
Y1 - 2019/11/4
N2 - IODP Expedition 340 successfully drilled, for the first time, large and likely tsunamigenic volcanic island arc landslide deposits. These cores provide evidence and tests of previous hypotheses for the composition, origin, and mode of transport of those deposits. Sites in the medial to distal parts of the landslide deposits offshore Montserrat and Martinique recovered seafloor sediment, comprising turbidites and hemipelagic deposits, and lacked the coarse and chaotic subaerial volcanic debris avalanche material. This supports the concepts that (i) the volcanic debris avalanche component of these landslides is restricted to proximal areas and tends to stop at the slope break and (ii) emplacement of volcanic debris avalanches in marine settings can trigger widespread and voluminous failures of preexisting low‐gradient seafloor sediment. The most likely mechanism for generating these large‐scale seafloor sediment failures appears to be the propagation of a décollement, from proximal areas that are loaded and incised by a volcanic debris avalanche. These results have implications for the magnitude of tsunami generation by volcanic island landslides. Volcanic island landslides composed of mainly seafloor sediment may form smaller magnitude tsunamis than equivalent volumes of subaerial block‐rich mass flows rapidly entering water.
AB - IODP Expedition 340 successfully drilled, for the first time, large and likely tsunamigenic volcanic island arc landslide deposits. These cores provide evidence and tests of previous hypotheses for the composition, origin, and mode of transport of those deposits. Sites in the medial to distal parts of the landslide deposits offshore Montserrat and Martinique recovered seafloor sediment, comprising turbidites and hemipelagic deposits, and lacked the coarse and chaotic subaerial volcanic debris avalanche material. This supports the concepts that (i) the volcanic debris avalanche component of these landslides is restricted to proximal areas and tends to stop at the slope break and (ii) emplacement of volcanic debris avalanches in marine settings can trigger widespread and voluminous failures of preexisting low‐gradient seafloor sediment. The most likely mechanism for generating these large‐scale seafloor sediment failures appears to be the propagation of a décollement, from proximal areas that are loaded and incised by a volcanic debris avalanche. These results have implications for the magnitude of tsunami generation by volcanic island landslides. Volcanic island landslides composed of mainly seafloor sediment may form smaller magnitude tsunamis than equivalent volumes of subaerial block‐rich mass flows rapidly entering water.
KW - Debris avalanche deposit
KW - International ocean discovery program
KW - Lesser antilles arc
KW - Subaerial instability
KW - Submarine instability
KW - Submarine landslide deposit
KW - Submarine landslides offshore volcanic islands
KW - Tsunami hazard
UR - http://www.scopus.com/inward/record.url?scp=85097370509&partnerID=8YFLogxK
U2 - 10.1002/9781119500513.ch17
DO - 10.1002/9781119500513.ch17
M3 - Chapter
AN - SCOPUS:85140341358
SN - 9781119500582
T3 - Geophysical Monograph Series
SP - 277
EP - 297
BT - Submarine Landslides
PB - Wiley-VCH Verlag
ER -
