Fine Structure of Methane Hydrate-Bearing Sediments on the Blake Outer Ridge as Determined from Deep-Tow Multichannel Seismic Data
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 10, 1993
- Accession Number
- ADA262041
Entities
People
- J. F. Gettrust
- M. M. Rowe
Organizations
- United States Naval Research Laboratory