A seismic velocity inversion on Bjørnøya — The western Barents Shelf

Seismic velocity measurements on the exposed Triassic to Cambro-Silurian sedimentary sequence on Bjørnøya show a velocity inversion in the stratigraphic section with a minimum velocity (3.8 km/s) in the Devonian fluvial sandstones of the Røedvika Formation, which also has the highest porosity (～ 17%). The low porosity in the younger formations is due to silicification and dolomitization probably by chemical alterations of the pore water rather than an overburden effect. Sonobuoy measurements in the vicinity of Bjørnøya show seismic velocities at the sea floor comparable with velocities of the exposed formations on the island itself.