The southern flank of the Storegga slide: Imaging and geomorphological analyses using 3D seismic

Abstract

The Holocene Storegga Slide is one of the world's largest exposed slides and also the most studied of all the Norwegian slides. However due to its complexity it is far from being fully understood. Three-dimensional (3D) seismic combined with swath bathymetry data from the southern flank of the Storegga Slide have been used to study mass movement processes occurring in the region. The high spatial resolution provided by the 3D seismic data has allowed a detailed geomorphological analysis of sedimentary and deformational structures. The Holocene Storegga failure affected a significant part of the studied area. The predominant feature is a compression zone, comprising two lobes, where the seabed shows marked parallel ridges. Down slope it is possible to identify another compression zone. A relative chronology of events was established and it is proposed that these two compressions zones are the result of gravity-driven slope failures related to different stages of the Holocene Storegga Slide.