GIS Catalogue of Submarine Landslides in the Spanish Continental Shelf: Potential and Difficulties for Susceptibility Assessment

This study presents the first version of a GIS catalogue of submarine landslides affecting the Spanish Continental Shelf pursuant UNCLOS (United Convention for the Law of the Sea) that comprise continental-type margins (Atlantic and Mediterranean) as well as hot-spot type volcanic islands and seamounts (Canary Archipelago). This first version compiles a total of 223 submarine landslides within an area of 1.5 million square kilometres. This catalogue, developed in a geographic information system, compiles information of each submarine landslide such as the name, location, typology, age, volume, source, dimensions (width, elongation), minimum and maximum height, minimum and maximum seafloor slopes. As a direct application and advantage of this digital catalogue, a first approach to a susceptibility map has been elaborated using GIS analysis tools taking into account the following available factors sourced from the geological maps of the Spanish continental margins: (i) faults map, (ii) active faults map, (iii) earthquakes density map, (iv) seafloor slope map and (v) seabed composition map. The potential and difficulties of this GIS catalogue of landslide as a first step in the submarine risk analysis are discussed. This first version of the GIS catalogue is conceived as the origin of a national submarine landslides database within the European network, which is being built as part of the EMODNET-Geology project.