Mapping of areas affected by undefined landslides at the present-day seafloor on the eastern lower continental slope of the Cantabrian continental margin (Bay of Biscay)

For the mapping of the canyon features a database with over 1500 km of 2D multi- and single-channel seismic lines, with different degrees of resolution (from a few metres to metric) together with high-resolution multi-beam bathymetry has been analysed and interpreted. Multi-channel seismic records were downloaded from the Archivo Técnico de Hidrocarburos (https:// geoportal.minetur.gob.es/ATHv2/welcome.do). Single-channel records were mostly obtained with airgun systems (140 to 530 c.i.) and are included in the database from the Instituto de Ciencias del Mar, ICM-CSIC, http://www.icm.csic.es/geo/gma/SurveyMaps. Several multi-beam bathymetry datasets obtained with Simrad EM12 and Atlas HYDROSWEEP DS multibeam echosounders were also compiled and integrated for the present study from the MARCONI, CONTOURIBER, MOWER and BARACA projects, the Fishing General Secretary (Spanish Government) and the EMODnet bathymetry. These data were gridded to a resolution of 200, 100 and 50 m.