Fine structure of methane hydrate-bearing sediments on the Blake Outer ridge as determined from deep-tow multichannel seismic data. (Reannouncement with new availability information). Final report

Technical Report · Fri Jan 01 04:00:00 EST 1993

OSTI ID:200115

Rowe, M M; Gettrust, J F

High-resolution, deep-tow multichannel seismic data are used to investigate the detailed structure of sediments containing methane hydrate. These data support thick, laterally extensive layers of methane hydrate-bearing sediment underlain by a bottom simulating reflector (BSR) and spatially discontinuous zones of hydrate within the sediments above the BSR depth where no BSR is present. These data resolve normal faults which extend from the surface through the BSR with apparent offsets of up to 20 m. A phase inversion identified at the top of the BSR shows that the material immediately beneath the BSR has anomalously low velocity, consistent with a layer of sediment containing free methane gas. The fault offsets along the BSR and consistent with a pressure change of approx. 200 kPa (approx. 2 bars) across the fault zone.... Directional ambient noise, Bottom scattering, Deep-towed array geophysical system, Towed array, Ocean-bottom seismometer

• Research Organization: Naval Research Lab. Detachment, Stennis Space Center, MS (United States)
• OSTI ID: 200115
• Report Number(s): AD-A--262041/7/XAB
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
COASTAL WATERS
EXPLORATION
FINE STRUCTURE
GEOPHYSICAL SURVEYS
HYDRATES
METHANE
SEDIMENTARY BASINS
SEISMOGRAPHS