Publication Date:
2022-11-16
Description:
Submarine landslides can destroy seafloor infrastructure and generate devastating tsunamis, but in spite of decades of research into the functioning of submarine landslides there are still numerous open questions in particular how different phases of sliding influence each other. Here, we re-analyse the Ana Slide - a relatively small (〈1 km3) landslide in the Balearic Islands, which is unique because it is completely imaged by high-resolution 3D seismic data. The Ana Slide comprises three domains: (i) a source area that is almost completely evacuated with evidence of headscarp retrogression; (ii) an adjacent downslope translational domain representing a bypass zone for the material that was mobilized in the source area, and (iii) the deposit formed by the mobilized material, which accumulated downslope in a sink area. Isochron maps show deep chaotic seismic units underneath the thickest deposits. We infer that rapid deposition of the landslide material deformed the underlying sediments. A thin stratified sedimentary unit between three lobes shows that the Ana Slide evolved in two failure stages separated by several tens of thousands of years. This illustrates the danger of over-estimating the volume of mobilized material and under-estimating the complexity even of relatively simple slope failures without high-quality seismic data.
Type:
Article
,
NonPeerReviewed
Format:
text
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