Bottom Simulating Reflector in the western Ross Sea, Antarctica

Seismic evidence of gas hydrates and free gas in the western Ross Sea (Antarctica) is inferred from the occurrence of a bottom simulating reflector. It evolves into cross-cutting reflectors and enhanced-amplitude reflectors from the deeper basin to an intra-basin struc- tural high. In addition to the seismic data, the presence of free gas is suggested by the occurrence of gas-seeping seafloor morphologies like mud volcanoes and pock- marks. The upward gas migration is controlled by the presence of faults, connecting the free gas zone below the BSR to the mud volcanoes and pockmarks on the seafloor.