Acoustic Observation of the Time Dependence of the Roughness of Sandy Seafloors

Abstract

A statistical model for the time evolution of seafloor roughness due to biological activity is applied to photographic and acoustic data. In this model, the function describing small scale seafloor topography obeys a time-evolution equation with a random forcing term that creates roughness and a diffusion term that degrades roughness. When compared to acoustic data from the 1999 and 2004 Sediment Acoustics Experiments (SAX99 and SAX04), the model yields diffusivities in the range from 3.5 xlO-11 to 2.5 xlO-10 m2s-1 (from 10 to 80 cm2yr-1), with the larger values occurring at sites where bottom-feeding fish were active. While the experimental results lend support to the model, a more focused experimental and simulation effort is required to test several assumptions intrinsic to the model.

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Document Details

Document Type
Technical Report
Publication Date
Nov 25, 2009
Accession Number
ADA513703

Entities

People

  • Anthony P. Lyons
  • Christopher D. Jones
  • Dajun Tang
  • Darrell R. Jackson
  • Kevin B. Briggs
  • Kevin L. Williams
  • Michael D. Richardson

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Ground and Sea Platforms
  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Acoustic Measurement
  • Acoustic Phenomena
  • Acoustic Properties
  • Acoustic Scattering
  • Acoustic Waves
  • Acoustics
  • Computational Science
  • Equations
  • Oceanography
  • Physical Properties
  • Physics
  • Physics Laboratories
  • Scattering
  • Sedimentation
  • Time Dependence
  • Topography
  • Two Dimensional

Readers

  • Acoustical Oceanography.
  • Computational Modeling and Simulation
  • Materials Science and Engineering.