Seafloor craters and mounds in the central Barents Sea

Abstract

Multiple giant craters and mounds have been identified in the area of the Upper Bjørnøyrenna in the central Barents Sea from the reflection seismic and echo sounder data. Analysis of seismic and echo sounder data revealed clear connection between these distinct seafloor features and seismic amplitude anomalies. Distribution pattern of the numerous water column anomalies registered in the area and interpreted to be gas plumes, corresponds to the location of faults in the study area what suggest that gas is of thermogenic origin and is migrating from the deeper reservoir through porous layers and faults working as vertical conduits. Suggested that craters and mounds are collapsed depressions and collapsed gas hydrate pingoes and their formation is associated with the processes of formation and decomposition of shallow gas hydrates due to the last glaciation period in the area, the Late Weichselian Maximum.