Accession Number : ADA262041


Title :   Fine Structure of Methane Hydrate-Bearing Sediments on the Blake Outer Ridge as Determined from Deep-Tow Multichannel Seismic Data


Descriptive Note : Journal article


Corporate Author : NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEAN SCIENCES BRANCH


Personal Author(s) : Rowe, M M ; Gettrust, J F


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a262041.pdf


Report Date : 10 Jan 1993


Pagination or Media Count : 12


Abstract : 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.


Descriptors :   *HYDRATES , *SEISMIC DATA , *ACOUSTIC SCATTERING , *SEDIMENTS , *METHANE , *OCEAN BOTTOM , REPRINTS , SCATTERING , TOWED ARRAYS , LOW VELOCITY , PRESSURE , SEISMOMETERS , MULTICHANNEL , OCEAN RIDGES , REFLECTORS , OCEAN BOTTOM TOPOGRAPHY , SEISMIC VELOCITY , AMBIENT NOISE , HYDROPHONES , INVERSION , ACOUSTIC ARRAYS , SURFACES , FAULTS(GEOLOGY) , HIGH RESOLUTION , DEPTH


Subject Categories : Organic Chemistry
      Physical and Dynamic Oceanography
      Seismology


Distribution Statement : APPROVED FOR PUBLIC RELEASE