Processing and interpretation of water column data from the Gardarbankhøgda, Bjarmelandplattformen, Sentralbankhøgda and Kong Karls Land-plattformen, Barents Sea

Abstract

This study was carried out using multibeam echo sounder data collected during Mareano surveys in 2015, 2017, 2018 and 2021. The data from the surveys have been processed and interpreted to identify natural gas seeps, visible as gas flares, in the water column data. The data is also used for extracting bathymetry and backscatter.The study area lies on Gardarbankhøgda, Bjarmalandplattformen, Sentralbankhøgda and Kong Karls Land-plattformen in the southern Barents Sea. The subsurface geology consists of eroded sediments from Jurassic to middle Triassic age. The shallowest area lies on Gardarbankhøgda, with the seafloor deepening towards Bjarmelandplattformen and Kong Karls Land-plattformen. The subsurface architecture follows a similar trend and therefore subsurface fluid flow is southwards from Kong Karls Land-plattformen and northwards from Bjarmelandplattformen guided by the stratification. The water depth is shallow and ranges from 54 to 370 m with the shallowest part at the north-western part of Gardarbankhøgda.The following results were obtained:-Processing and interpretation of water column data covering 5410 km2 from the study area in the Southern Barents Sea using Fledermaus Midwater software indicates 725 flares of varying sizes and confidence levels.-Flares are categorized according to the standard methods used in Mareano and other projects.-105 flares with a magnitude higher than 4 were identified, thus representing ~15% of total flares.