This has led to the occurrence of several high magnitude earthquakes (Mw > 7), of which the 1755 Lisbon Earthquake and tsunami is one of the major documented natural disasters 17. This is an area of relevant geological risk, with frequent seismic activity resultant from the NW-ward collision of the African and European tectonic plates 15, 16. Such is the case of the West and Southwest Iberian Margin, on the Northeast Atlantic Margin. However, extensive submarine landslide characterisation is still lacking in many continental margins, and adequate characterisation depends on the quality of available data. Global data compilations have also allowed the comparison of landslides in distinct geological settings 7, 13, 14. Regional compilations are available from the US Atlantic margin 8, 9, the Mediterranean Sea 10, the Spanish margins 11 or Australia 12. It is thus crucial to understand the distribution patterns and morphometric trends of submarine landslides according to the regional setting in which they occur, and aim to unravel insights on their causes and deposits 1, 7.Įfforts have been made to compile databases of submarine landslides to better understand their distribution and characteristics in marine settings around the world 1, 7. Recognising submarine landslide extents has further political implication as these are used to set international ZEE boundaries under the definition of the UN Convention on Law of the Sea 6. Submarine landslides impact in marine biological communities, either by acting as habitat hotspots on their scars and remobilised elements or by disturbing and modifying seafloor ecology during emplacement 5. Moreover, geotechnical installations and infrastructures resting on the seafloor such as submarine communication cables, pipelines or any purpose-build platform are sensible to mass movements 4. Tsunamis generated from landslides on the flank of subaerial topography flowing into the sea 2, or from large collapses on fully submerged morphologic features 3 are a major concern. Submarine landslides are a primary geohazard in marine environments. Although singular massive deposits attract the attention for detailed studied, the regions where they occur can record geological evidence of hundreds or thousands of smaller-scale landslides, often poorly covered by available data and of limited focus of analysis. The resulting landslides can be characterised by a variety of deposit features and morphologies, influenced by the mechanic properties of the original strata, the dynamics of the flow processes, regional geology and seismicity. Submarine mass movements are common occurrences on marine domains, from the shallow coasts to the deepest areas of the oceans 1.
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