NEW INFORMATION ON SUBSEA PERMAFROST IN THE KARA SEA BASED ON SEISMIC REFRACTION DATA

For the first time, a large volume of first-arrival records in common shot gathers was processed and comprehensively analyzed for an area of 620 thousand sq km in the Kara Sea, from 74 CDP seismic lines of JSC MAGE with a total length of approximately 11.5 thousand km. It was demonstrated that, in the best-studied South Kara Basin, the degradation of subsea relic permafrost (frozen ground) mainly has finished. However, permafrost with different levels of ice cementing has remained in 174 isolated patches. These data are consistent with previous findings by JSC AMIGE specialists based on drilling engineering-geological wells. For the insufficiently studied North Kara Basin, fundamentally new information was obtained on the complete absence of relic permafrost, which is radically different from all other research results, primarily based on mathematical modeling. A hypothesis has been proposed about possible reasons for the preservation of permafrost isolated patches in the South Kara Basin.

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