Flow Behaviour of a Giant Landslide and Debris Flow Entering Agadir Canyon, NW Africa
Agadir Canyon is one of the largest submarine canyons in the World, supplying giant submarine sediment gravity flows to the Agadir Basin and the wider Moroccan Turbidite System. While the Moroccan Turbidite System is extremely well investigated, almost no data from the source region, i.e. the Agadir Canyon, are available. New acoustic and sedimentological data of the Agadir Canyon area were collected during RV Maria S. Merian Cruise 32 in autumn 2013. The data show a prominent headwall area around 200 km south of the head of Agadir Canyon. The failure occurred along a pronounced weak layer in a sediment wave field. The slab-type failure rapidly disintegrated and transformed into a debris flow, which entered Agadir Canyon at 2500 m water depth. Interestingly, the debris flow did not disintegrate into a turbidity current when it entered the canyon despite a significant increase in slope angle. Instead, the material was transported as debrite for at least another 200 km down the canyon. It is unlikely that this giant debris flow significantly contributed to the deposits in the wider Moroccan Turbidite System.
KeywordsSubmarine landslide Debris flow Acoustic imaging Agadir Canyon
We thank all scientists and crew of RV Merian Cruise MSM32 in autumn 2013 for their support during data collection. The authors are thankful to Jason Chaytor and David Völker for their reviews and constructive comments. Financial support was provided by the Deutsche Forschungsgemeinschaft and the UK Natural Environment Research Council (NERC grant NE/J012955/1).
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