Problems and technologies of offshore permafrost investigation

摘要

The article describes the state of the art methods and technics of soil investigation in specific Arctic offshore areas. Underwater sediments can be frozen and hazardous for various offshore constructions, particularly, for marine pipelines, platforms and near-shore terminals. Sub-bottom permafrost is an object of special investigation and technologies. The zone is currently exposed to severe climate and was chilled for a long time in the past. Reliable thickness of offshore permafrost is up to 100m according to direct methods. Both top and bottom permafrost are hardly detectable offshore. Special knowledge and good experience are indispensable even to recognize its location and extent. Standard methods are not always applicable for its recognition, that is why more sophisticated technique is required. Combination of integrated approaches is the only way to detect marine permafrost and characterize its properties and location.