LITHOLOGICAL AND GEOCHEMICAL INDICATORS OF ICE GOUGING: EVIDENCES FROM HOLOCENE SEDIMENTS IN THE EAST SIBERIAN SEA
A.V. Alatortsev1, A.N. Kolesnik1, X. Shi2, L. Hu3, V.N. Karnaukh1, A.S. Astakhov1
1V.I. Il’ichev Pacific Oceanological Institute, Far Eastern Branch of the Russian Academy of Sciences, Vladivostok, Russia
2First Institute of Oceanography, Ministry of Natural Resources of China, Qingdao, China
3Ocean University of China, Qingdao, China
Keywords: Ice gouging, bottom sediments, Holocene, lithology, geochemistry, East Siberian Sea
Abstract
Cores of Holocene bottom sediment collected in the East Siberian Sea revealed layers with mixed textures and layers with breaks in sedimentation corresponding to the two sea levels defined as modern (upper) and Early Holocene (lower). The layers are characterized by distinctly chaotic variability in textural pattern (mottled appearance, multidirectional banding), colorimetric and geochemical parameters (sawtooth-like distribution curves). Such character of changes is associated with the physical action of dragging keels of ice/icebergs exerted on the seafloor and is referred to as ice gauging (scouring). Its analysis can be used for identification of ice scour-affected layers in other sediment cores collected in this region, and for the purpose of creating a representative database, predicting their occurrence and developing adequate measures to minimize the damaging impact from drifting sea ice and icebergs on the seafloor within the bounds of the Arctic shelf.
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