The map service incorporates submarine slides. Slides are presented as polygons in addition to boundaries of the slides. The data has been compiled from several sources, with differing details. The main source for the slides on the Norwegian continental shelf is the Seabed project (Norwegian Deepwater Programme, Seabed project Phase II. Mid-to Late Cenozoic Geomodel of the Mid-Norwegian Continental Margin. Atlas volume (Report no. SP2-02-FS-01R-00003-04); By Fugro Survey Ltd., BGS, NGU). For slides in the other countries, the COSTA project (COSTA - Continental Slope Stability, 2004. Ed. J. Mienert. Marine Geology 213, 1-4, pp. 1-504) is the main source. Minor sources include various scientific publications and the Norwegian MAREANO project. Source information is available through the info button in the map service.