The Gebra slide: a submarine slide on the Trinity Peninsula Margin, Antarctica
Imbo, Y.; De Batist, M.; Canals, M.; Prieto, M.J.; Baraza, J. (2003). The Gebra slide: a submarine slide on the Trinity Peninsula Margin, Antarctica. Mar. Geol. 193(3-4): 235-252. dx.doi.org/10.1016/S0025-3227(02)00664-3
In: Marine Geology. Elsevier: Amsterdam. ISSN 0025-3227; e-ISSN 1872-6151, more
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| Keywords |
Antarctic Peninsula
Ice ages
Sedimentation > Glacial sedimentation
Transport > Sediment transport > Mass gravity transport (sediments) > Debris flow
Vehicles > Underwater vehicles > Manned vehicles > Submarines
PSW, Antarctica, Antarctic Peninsula [Marine Regions]; PSW, Antarctica, Bransfield Strait [Marine Regions]
Marine/Coastal |
| Author keywords |
Gebra Slide; Antarctic Peninsula; glacial continental margin; submarine slope stability; debris flow |
| Authors | | Top |
- Imbo, Y., more
- De Batist, M., more
- Canals, M.
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| Abstract |
A large submarine slide - the Gebra Slide - has been discovered on the continental margin of Trinity Peninsula, Central Bransfield Basin, Antarctic Peninsula. The slide scar is clearly expressed in the bathymetry and is cut into the toe of the glacial-period slope-prograding strata on the lower continental slope. Seismic data give evidence of an associated debris-flow deposit embedded in the interglacial-period basin-fill strata of the basin floor. The total volume of sediment involved in the mass movement is about 20 km3. Indirect dating of the mass-wasting event, based on seismic-stratigraphic relationships of the slide scar and associated debris-flow deposit with underlying glacial-period slope units and the overlying interglacial-period basin-floor units, suggests that it took place at the transition between the last glacial period and the present-day interglacial. The initiation of the Gebra Slide is attributed to a combination of several factors, such as high sedimentation rates during the last glacial period, the unloading effect of a retreating ice sheet during deglaciation, pre-existing tectonic fabric and high seismicity in the area. This is the first recent submarine slide of this size identified on the glacial, continental margins of Antarctica. In morphology and general characteristics it is quite similar to the well-known large-scale submarine slides from the northern hemisphere glacial margins, although it is smaller. Its most striking characteristic is its lower-slope position (at 1500-2000 m of water depth), which remains up to now difficult to explain. |
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