Sediment starved passive margins, particularly those of insular slopes,display significant mass transport activity despite the absence ofenvironmental stresses from high sedimentation rates. The “MenorcaChannel” represents the up to 120 m deep shelf sector connectingthe Menorca and Mallorca Islands (Balearic Islands – WesternMediterranean). South of the Menorca Channel submarine gravitationalprocesses have been mapped and interpreted from swath-bathymetry,TOPAS parametric echosounder and deep-towed videos. The shelf-breakis located at an average depth of 140 m, and sediment instability is awidespread phenomenon. The slope region south the Menorca Channelshows a number of submarine canyons disrupting the outer shelf. Thenorth-easternmost canyon is the more active feature, with an incisedaxis and scars shaping the flanks up to their edges. Headwall scarps,between 140 and 700 m depth, are up to 20 m high. The shallowerscarps producing slab-type failures have carved the outer edges ofplanar sedimentary bodies interpreted as formed in shallow environmentsduring previous glacial stages. Results show that a variety of sedimentinstability processes extensively shape the southern upper slope of theMenorca Channel. Submarine canyons develop on the Emile BodoutEscarpment (EBE), a passive tectonic feature which bounds the sloperegion of the study area. A number of knickpoints within the canyonssuggest backward erosion control on mass wasting and, at the sametime, that slope failure is one of the main drivers for canyon upslopemigration. Steep gradients of the upper slope, the presence of weak layersand the action of major storms during lowstand stages are additionalfactors likely to influence the distribution and frequency of mass wastingprocesses in this area.
|Titolo della pubblicazione ospite||Submarine Mass Movements and Their Consequences|
|Numero di pagine||10|
|Stato di pubblicazione||Published - 2014|
All Science Journal Classification (ASJC) codes