Eivissa slides, western Mediterranean Sea: morphology and processes
|Author(s)||Lastras Galderic1, Canals M1, Amblas D1, Ivanov M2, Dennielou Bernard3, Droz Laurence4, Akhmetzhanov A5|
|Affiliation(s)||1 : Univ Barcelona, GRC Geociencies Marines, E-08028 Barcelona, Spain.
2 : Moscow MV Lomonosov State Univ, UNESCO, Ctr Marine Geol & Geophys, Moscow 199899, Russia.
3 : IFREMER, DROGM, F-29280 Plouzane, France.
4 : Univ Bretagne Occidentale, CNRS, F-29280 Plouzane, France.
5 : Natl Oceanog Ctr, Southampton SO14 3ZH, Hants, England.
|Source||Geo-Marine Letters (0276-0460) (Springer), 2006-10 , Vol. 26 , N. 4 , P. 225-233|
|WOS© Times Cited||30|
|Keyword(s)||Morphology, Bathymetry, Slides, Mediterranean sea, Eivissa channel|
|Abstract||After obtaining full-coverage swath bathymetry data in 1995 and very high-resolution acoustic profiles in 2002, four slides at the Balearic Margin of the Eivissa Channel in the western Mediterranean Sea were revisited in 2004 when side-scan sonar data were collected using a MAK-1M deep-towed acoustic system. These new findings, higher in resolution than those for the swath bathymetry, show two main features previously undetected within these submarine landslides: (1) a series of step-forming inclined and detached slabs oriented perpendicular to the slide movement and located in the uppermost part of the slides, and (2) arcuate regular positive ridges oriented also normal to the slide movement and located in the depositional lobes of some of the slides. The former are interpreted as extensional ridges, suggesting a retrogressive post-failure evolution of the slides. The latter are interpreted as compression ridges, related to plastic deformation of the sediment before movement freezing. Moreover, the new data show that fluid escape features are even more widespread in the Eivissa Channel than previously thought, dozens of new pockmarks less than 20 m in diameter having been identified.|