Faulted Structure of the Bottom Simulating Reflector on the Blake Ridge, Western North Atlantic

High-resolution multichannel seismic data collected from the Blake Ridge in the western North Atlantic by the Naval Research Laboratorys Deep Towed AcousticsGeophysics System DTAGS show that the bottom simulating reflector BSR in this area is the reflection from the interface between an approx. 440-m-thick section of hydrate bearing sediment overlying and approx. 5- m-thick layer of methane gas-rich sediment. The high resolution attainable by the deep-tow seismic system reveals normal fault offsets of approx. 20 m in the BSR. These growth faults may provide a path for vertical migration of methane initially concentrated beneath the hydrate-bearing sediment, enabling hydrate to form throughout sediment above the BSR. Because the BSR represents a methane gas methane hydrate phase boundary rather than a lithologic or diagenetic horizon, the observed off set of the BSR itself reflects discontinuities in the pressure- temperature field across the fault zones where they intersect the BSR. Directional ambient noise, Bottom scattering, Deep-towed array geophysical system, Ocean-bottom seismometer, Towed array.