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Gas hydrates contain more carbon than does any other global reservoir and are abundant on continental margins worldwide. These two facts make gas hydrates important as a possible future energy resource, in submarine landsliding and in global climate change. With the ongoing global warming, there is a need for a better understanding of the distribution of gas hydrates and their sensitivity to environmental changes. Gas hydrate systems in polar latitudes may be of particular importance due to the fact that environmental changes will be felt here first and most likely are more extreme than elsewhere. A bottom-simulating reflector (BSR) that reflects the base of the gas hydrate stability zone (GHSZ) provides geophysical evidence for gas hydrates on the mid-Norwegian margin, in the Barents Sea and on the margins to the west and north of Svalbard. Although located quite distant from each other, the gas hydrate settings show considerable similarity in terms of the sedimentary environment, in which they occur. Gas hydrates primarily occur within contouritic and hemipelagic deposits. They are absent within glaciogenic sediments that were deposited by debris flows during maximum glaciations. Thick sedimentary formations, close-by deep-seated petroleum systems and an active fluid flow regime are among the factors that condition the occurrence of gas hydrates at these locations. The Norwegian-Barents Sea-Svalbard (NBS) margin has experienced significant environmental changes during the last deglaciation that must have led to changes in gas hydrate stability. As a result, gas hydrates on the NBS margin are associated with large submarine landslides, seafloor craters and fluid-venting systems.
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