Slope failure dynamics and impacts from seafloor and shallow sub-seafloor geophysical data: case studies from the COSTA project

• Main Authors: Canals, M, Lastras, G, Urgeles, R, Casamor, JL, Mienert, J, Cattaneo, A, De Batist, Marc, Haflidason, H, Imbo, Yannick, Laberg, JS, Locat, J, Long, D, Longva, O, Masson, DG, Sultan, N, Trincardi, F, Bryn, P
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier Science 2004
• Subjects: Earth and Environmental Sciences; COSTA project; BIG’95 Slide; mid-Norwegian margin; Antarctic; The Antarctic; Antarctic Peninsula; Storegga; Finneidfjord; Antarc*
• Online Access: https://biblio.ugent.be/publication/298430; http://hdl.handle.net/1854/LU-298430

Holocene and slightly pre-Holocene submarine landslide are found both in high-latitude glacial-dominated margins and in lower latitude, river-dominated margins. This paper constitutes a major assessment on some of the best-studied submarine instabilities in the world. We review and update from original data and literature reports the current state of knowledge of Storegga, Traenadjupet and Finneidfjord slides from the mid-Norwegian margin, Afen Slide from the Faeroe-Shetland Channel, BIG’95 Slide and Central Adriatic Deformation Belt (CADEB) from continental slope and inner continental shelf settings off the Ebro and Po rivers in the Mediterranean Sea, Canary Slide west of the westernmost, youngest Canary Islands and Gebra Slide off the northern tip of the Antarctic Peninsula in the southern hemisphere, i.e. those studied in the Continental Slope Stability (COSTA) project. The investigated slides range in size from the gigantic 90,000 km2 and almost 3000 km3 Storegga Slide to the tiny 1 km2 and 0.001 km3 Finneidfjord Slide. Not only do individual submarine landslides rarely involve processes precisely fitting with pre-established categories, mostly based on subaerial research, but also they display complex mechanical behaviors within the elastic and plastic fields. Individual events can involve simultaneous or successive vertical to translational movements including block detachment, block gliding, debris flow, mud flow and turbidity currents. The need for an in-depth revision of the classification criteria, and eventually for a new classification system, based on the new imaging capabilities provided by modern techniques, is more than obvious. We suggest a new system, which, for the moment, is restricted to debris flows and debris avalanches. Volume calculation methods are critically reviewed and the relations between some key geomorphic parameters are established for the selected slides. The assumed volume missing from scar areas does not necessarily match the actual volume of sediment remobilised by an ...