Slope Failures Of The Flanks Of The Southern Cape Verde Islands
The flanks of the Cape Verde Islands Fogo, Brava and Santiago show extensive evidence of past and potential slope failure. Analyses of bathymetric and subaerial datasets show debris avalanches, turbidite pathways and debris flows, with the transportation of large volumes of rock and sediment. Similarities are seen with many of the processes operating on the flanks of the Canary Islands. In this paper we show the use of different multibeam bathymetry systems for geomorphological description and quantitative analysis. Slope maps, profiles and backscatter analysis can be used to classify the bathymetric characteristics. These derivative processes delineate the size and shape of the debris avalanches and flows and identify channel systems, as well as areas of recent seafloor volcanic activity. Two distinct debris fields covering at least 2000 km2 sourced from the east coast of Fogo are thought to contain up to 250km3 of material. Large slope failures, such as those from Fogo, may result in damage to seafloor installations such as submarine cables. However, greater hazards may be posed by the consequent generation of tsunamis.
KeywordsTransportation Radar Turbidity Holocene Lithosphere
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