The Arctic cryosphere is one of the most sensitive indicators of climate change. Arctic permafrost encloses enormous hydrocarbon reserves as methane gas hydrates (up to 32 000 Gt). Global warming may appear as a consequence of the melting of permafrost, decomposition of gas hydrates, and the discharge of large volumes of carbon (methane) into the atmosphere, which would provoke further temperature increases and rapid permafrost melting (positive feedback). Therefore, the distribution of subaqueous permafrost in Arctic seas represents one of the most urgent issues in the investigation of the climate system. At present, investigations in this field are limited. Temperature measurements have only occasionally been performed. Modeling of subaqueous permafrost distribution has usually been based on the assumption of equality between temperatures of bottom sediments and bottom waters, which does not necessarily correspond to the reality of certain areas of the Arctic shelf. This communication presents data on acoustic backscattering (ABS) at frequencies of 50 and 200 kHz and on bottom sediment temperature (BST) distribution in the Arctic shelf. Anomalously deep ABS positions (>10 ms at 50 kHz and >5 ms at 200 kHz) have been registered in many areas). In other areas of the World Ocean, the ABS value at these frequencies is usually 3-5 ms or less. Such anomalously deep ABS was observed in shelf areas with negative BST, suggesting the existence of permafrost in these areas.
|Number of pages||3|
|Journal||Doklady Earth Sciences|
|Publication status||Published - Jun 2005|
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Earth and Planetary Sciences (miscellaneous)