A Comparison of Bistatic Scattering from Two Geologically Distinct Abyssal Hills

Abstract

The bistatic scattering characteristics of two geologically distinct abyssal hills located on the western flank of the Mid-Atlantic Ridge, known as B' and C', are experimentally compared using data acquired with low-frequency towed-array systems at 1/2 convergence zone (~33 km) stand-off. The comparison is significant because the abyssal hills span the two classes of elevated seafloor crust that cover the Mid-Atlantic Ridge. The highly lineated B' feature is representative of abyssal hills composed of outside corner crust, the most commonly occurring category, whereas the domed C' promontory is representative of the rougher, low-aspect-ratio abyssal hills composed of inside corner crust. The latter are less common and usually restricted to segment valley margins. The mean biazimuthal scattering distributions of the two abyssal hills each exhibit Lambertian behavior with comparable albedos, suggesting that the distinction between abyssal hills composed of differing crust is not significant in modeling long-range reverberation. The adverse effect of using bathymetry that undersamples seafloor projected area in scattering strength analysis is also quantified with data from the B' ridge. Specifically, the use of undersampled bathymetry can lead to significant overestimates in the strength of seafloor scattering.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2000
Accession Number
ADA640632

Entities

People

  • Chin S. Chia
  • Laurie T. Fialkowski
  • Nicholas C. Makris

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustics
  • Aspect Ratio
  • Backscattering
  • Distribution Functions
  • Frequency
  • Frequency Bands
  • High Resolution
  • Measurement
  • Ocean Ridges
  • Peak Values
  • Reverberation
  • Ridges
  • Scattering
  • Standards
  • Towed Arrays
  • Transmission Loss
  • Two Way Transmission

Readers

  • Acoustical Oceanography.
  • Regression Analysis.
  • Seismology