Seismic Velocity, Stratigraphy and Acoustic Study of the South China Sea.
Abstract
A study was performed of the seismic velocity structure of the South China Shelf from the westernmost parts of the Beibu Gulf, adjacent to the Gulf of Tonkin, south of Hainan Island and offshore southern mainland China, as far east as 118 deg east. Stacking velocities from petroleum industry multichannel seismic surveys were compiled into a database from which the depth or two way travel time to any given velocity interval could be calculated. The data was filtered to remove major decreases in velocity with depth, as these normally reflected decreasing data quality below -3 km. Data quality is typically good to 3 km, the approximate level of basement, and shows a good correlation with pre-existing seismic velocity data from sonobuoys. Seismically the shelf sediments are usually flat bedded, with generally well defined reflective character. The slope does not appear to be strongly affected by slumping, although locally such disturbances ar,e noted. The seismic data show that the sediment thicknesses are greatest offshore the Pearl River Mouth (up to -5 km), where a large sedimentary basin is formed separated from the continental slope by an outer marginal basement high. Faulting in the basement is common and oriented coast-parallel. Later reactivation of these faults, sometimes results in their propagation to the seafloor.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1998
- Accession Number
- ADA354753
Entities
People
- Jian Lin
- Peter D. Clift
Organizations
- Woods Hole Oceanographic Institution