Accession Number:

ADA551229

Title:

An EM Survey of the New Jersey Continental Shelf

Descriptive Note:

Annual rept.

Corporate Author:

WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF GEOLOGY AND GEOPHYSICS

Personal Author(s):

Report Date:

1998-01-01

Pagination or Media Count:

5.0

Abstract:

Maps of sedimentary physical properties are essential to a complete understanding of processes shaping the continental shelf. We have demonstrated that measurements of electrical resistivity can provide exciting new insights into shelf structure, and aim to make electromagnetic EM surveys a routine component of seafloor classification programs. The first objective of this research is to image, in terms of electrical properties, buried paleo-channels within two regions surveyed in 3D by the Huntec seismic system Davies et al., 1992 Davies and Austin, 1997. These Huntec surveys identified several buried channels at a depth of around 10m below the seafloor. Channels found in the northern survey area and one set at the western end of the southern Huntec area are carved in a surface that is thought to represent an erosional surface exposed during a sealevel low-stand. A prominent channel surface that has also been mapped in 3D appears at the eastern end of the southern Huntec area, but this channel sits above the seismic reflector R and may mark a separate sealevel low-stand. The second objective is to investigate the porosity structure within the prominent current-carved sandbar features seen in bathymetry and also in sidescan data. The third objective is to characterize the electrical signature of several regions of notably high acoustic backscatter which lie at the northern tips of topographically high sandbars.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Seismology
  • Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE