Freshwater ice rafting: an additional mechanism for the formation of some high-latitude submarine pockmarks.

Autor: Paull, C. K., Ussler III, W., Borowski, W. S.
Zdroj: Geo-Marine Letters; Sep1999, Vol. 19 Issue 1/2, p164-168, 5p
Abstrakt: Submarine pockmarks are common features on high-latitude continental shelves, yet the mechanisms for their formation are poorly understood. Here we propose an additional mechanism for the formation of high-latitude pockmarks involving freshwater ice rafting. Freshwater seeping upward through the sediments freezes at the sediment–water interface when bottom waters are below 0°C. Thin layers of the frozen water containing some sediment are buoyant and can rise off the bottom as small ice rafts, thereby excavating a seafloor depression over time. Sediment in the ice rafts becomes entrained in bottom currents and is dispersed over a wide area. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index