Location accuracy of seabed nodes during 3D seismic survey for seep studying at Laptev sea.

Summary Recent years marine surveys have provided a large and important data for mapping gaseous emissions from the seabed (the so-called seeps) of the North Seas of Russia. A number of researchers associate these phenomena with the release of methane from buried layers of permafrost on the shelf of the Arctic seas, which can potentially change the ratio of greenhouse gases in the Arctic and affect global climate change. The several important questions on the structure, composition and nature of these phenomena still remain unresolved. One of the ways to solve the questions posed is to perform detailed 3D seismic survey of high accuracy. During the 73th scientific voyage of R/V “Akademik Mstislav Keldysh” (AMK), 3-D reconnaissance seismic survey with seabed nodes was carried out. To study the internal structure of the sedimentary cover around the mega seep, we use a 3D reflection seismic method with seabed seismic nodes. The observation template consists of 16 4-component seismic seabed nodes with 300 meters spacing in both directions. Despite the absence of differential corrections for GPS/GLONASS, the obtained positioning accuracy of nodes on the sea bottom is sufficient for carrying out 3-D seismic survey.