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c:/dev/skygeo/src/iso2stac/stac_output_dynamic/collection-geological_survey_of_norway/collection.json
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Multibeam echosounder data was recorded to identify acoustic anomalies (gas flares) indicating that gas is seeping from the seabed. Since 2010, water column data have been collected simultaneously with bathymetry data. The surveys were undertaken by commercial vendors, the Norwegian Defence Research Establishment (FFI), and the Norwegian Hydrographic Service (NHS) using Kongsberg Maritime EM710, EM712, EM122, EM304 and/or EM2040 multibeam echosounder systems (MBES). Fledermaus Midwater (FMMW) package was used to process water column data for detecting and analysing the acoustic anomalies. The water column raw data was loaded in FMMW, combined with navigation from bathymetry raw data and converted to GWC files. Several water column anomalies detected in the Barents Sea have been ground-truthed, confirming the presence of gas seeps. The coordinates, time of acquisition, water depth, and height of gas flares were recorded during the interpretation, along with the survey name and line ID. In addition, a subjective assessment of the apparent magnitude was assigned. A confidence estimate (10-100%) is provided based on an expert assessment.
Geologi Områder med naturbetingede farer Oseanografiske geografiske forhold Norway Digital Mareano Felles datakatalog Geologi Barents Sea Norwegian Sea gas seeps seabed marine sediment stability climate continental shelf methane gas flare water column data National geoscientificInformation
Gas seeps are phenomena on the seabed where gas seeps out from the bedrock or sediments. The gas in these seeps can have different origins, such as e.g., biogenic, thermogenic or abiotic processes, and the seeps can have great importance for both biology, seabed stability and climate.
Gas seeps