Title | Investigating the Timing, Processes and Deposits of One of the Worlds Largest Submarine Gravity Flows: The ‘Bed 5 Event’ Off Northwest Africa |
Publication Type | Book Chapter |
Year of Publication | 2010 |
Authors | Mosher, DC, Moscardelli, L, Baxter, CDP, Urgeles, R, R. Shipp, C, Chaytor, JD, Lee, HJ, Wynn, RB, Talling, PJ, Masson, DG, Stevenson, CJ, Cronin, BT, LeBas, TP |
Editor | Mosher, D, R. Shipp, C, Moscardelli, L, Chaytor, J, Baxter, CDP, Lee, HJ, Urgeles, R |
Book Title | Submarine Mass Movements and Their Consequences |
Series Title | Advances in Natural and Technological Hazards Research |
Volume | 28 |
Pagination | 463-474 |
Publisher | Springer Netherlands |
City | Dordrecht |
ISBN Number | 978-90-481-3071-9 |
Keywords | Earth and Environmental Science |
Abstract | 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 |
URL | http://dx.doi.org/10.1007/978-90-481-3071-9_38 |
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