TY - ECHAP
KW - Earth and Environmental Science
AU - David Mosher
AU - Lorena Moscardelli
AU - Christopher Baxter
AU - Roger Urgeles
AU - Craig Shipp
AU - Jason Chaytor
AU - Homa Lee
AU - R. Wynn
AU - P.J. Talling
AU - D.G. Masson
AU - C. Stevenson
AU - BT Cronin
AU - T. LeBas
AU - David Mosher
AU - Craig Shipp
AU - Lorena Moscardelli
AU - Jason Chaytor
AU - Christopher Baxter
AU - Homa Lee
AU - Roger Urgeles
AB - An extensive dataset of shallow sediment cores is used here to describe one of the Worlds most voluminous and extensive submarine gravity flows. The Bed 5 event, dated at ~60 ka, originated on the upper slope offshore Atlantic Morocco, in the vicinity of Agadir Canyon. The volume of initial failure was ~130 km 3 of sediment, and the failure appeared to rapidly disintegrate into a highly mobile turbidity current. Widespread substrate erosion beneath the flow occurred up to 550 km from the interpreted source, and is estimated to have added a further 30 km 3 of sediment. The flow spread upon exiting Agadir Canyon, with deposition occurring across both the Agadir Basin and Seine Abyssal Plain. Evidence for flow transformations and linked turbidite-debrite development can be found in both basins, and there are also indications for sediment bypass and fluid mud behaviour. A portion of the flow subsequently spilled out of the western Agadir Basin, and passed through the Madeira Channels prior to deposition on the enclosed Madeira Abyssal Plain at 5,400 m water depth. The total run-out distance along the flow pathway is about 2,000 km, with only about half of the pathway confined to canyon or channel environments. Our results show that large-volume submarine landslides can rapidly disintegrate into far-traveling fluid turbidity currents, and that deposi-tional processes within such flows may be complex and spatially variable
CY - Dordrecht
N2 - An extensive dataset of shallow sediment cores is used here to describe one of the Worlds most voluminous and extensive submarine gravity flows. The Bed 5 event, dated at ~60 ka, originated on the upper slope offshore Atlantic Morocco, in the vicinity of Agadir Canyon. The volume of initial failure was ~130 km 3 of sediment, and the failure appeared to rapidly disintegrate into a highly mobile turbidity current. Widespread substrate erosion beneath the flow occurred up to 550 km from the interpreted source, and is estimated to have added a further 30 km 3 of sediment. The flow spread upon exiting Agadir Canyon, with deposition occurring across both the Agadir Basin and Seine Abyssal Plain. Evidence for flow transformations and linked turbidite-debrite development can be found in both basins, and there are also indications for sediment bypass and fluid mud behaviour. A portion of the flow subsequently spilled out of the western Agadir Basin, and passed through the Madeira Channels prior to deposition on the enclosed Madeira Abyssal Plain at 5,400 m water depth. The total run-out distance along the flow pathway is about 2,000 km, with only about half of the pathway confined to canyon or channel environments. Our results show that large-volume submarine landslides can rapidly disintegrate into far-traveling fluid turbidity currents, and that deposi-tional processes within such flows may be complex and spatially variable
PB - Springer Netherlands
PP - Dordrecht
PY - 2010
SN - 978-90-481-3071-9
SP - 463
EP - 474
TI - Investigating the Timing, Processes and Deposits of One of the Worlds Largest Submarine Gravity Flows: The \textquoteleftBed 5 Event\textquoteright Off Northwest Africa
UR - http://dx.doi.org/10.1007/978-90-481-3071-9_38
VL - 28
ER -