CLOSED SUBMARINE TALIKS IN THE EASTERN PART OF THE LAPTEV SEA SHELF
Remediation of hydrocarbon resource base requires expanding search for new oil and gas. In this regard are very promising area of the Arctic Shelf of Russia. That is why the investigations of the cryolithozone of the shelf Arctic seas are extremely relevant to justify the effectiveness of the search for new deposits. According to the results of interpreting the materials of the seismoacoustic investigations there are found the submarine (underwater) non-through taliks in the eastern part of the Laptev Sea shelf. Research region covers an area of 128° to 136° EL and from 73° to 76° NL. For the geocryological dismemberment of the Quaternary incision used the materials of the expeditions of 1998, using seismoacoustic hardware "PARASOUND" which was kindly provided by Dr. Frank Nissen (Germany). The modern topography of the seabed in the eastern part of the Laptev Sea shelf is a gently sloping abrasion-accumulative plain with individual preserved foothills, which are relicts of subaerial relief, flooded paleo-valleys and estuaries of rivers, and also the thermokarst kettles. The bottom surface is horizontal, with individual little hills slightly prominent emission over the falls. The Holocene marine sediments are represented by silty sandy loams and silty clays. According to the results of the modeling the power of this layer varies from 0.5 to 4.0 m. In according to the results of the paleo-reconstruction the described territory was under the sea in a range of 9.3 to 9.8 thousand years ago. Also author investigated the morphology of submarine taliks and regularities of the lithological structures incision to a depth of 20 m, compiled a map of the current situation of taliks on the shelf, constructed geocryological spatial models that characterize the modern morphology and structure of the flooded depressions, and calculated speed of sedimentation. The average speed of Holocene active marine sediment accumulation and coastal marine sediment accounted for 12.9 cm/thousand years and 170 cm/thousands years, respectively.