Accession Number:

ADA608988

Title:

Evidence for High Nonlinearity in Sandy Sediment Using an Air Gun Source

Descriptive Note:

Memorandum rept. Jun 2010

Corporate Author:

NAVAL OCEANOGRAPHIC OFFICE STENNIS SPACE CENTER MS ACOUSTICS DIVISION

Personal Author(s):

Report Date:

2014-07-03

Pagination or Media Count:

33.0

Abstract:

An airgun source near the seafloor was used to initiate weakly nonlinear acoustic waves that propagated down into a sandy sediment. Below the airgun at an appropriate offset were two 12-element vertical arrays to monitor the waves evolution from 10 cm above the seafloor to a depth of 1 meter in the seafloor. Analysis of the resulting waveforms gave values of log-pressure increase with time that are too large to be explained by linear theory, or even fluid-like nonlinearity. We investigate the possibility that nonlinearities inherent to granular media are responsible for the observations

Subject Categories:

  • Physical and Dynamic Oceanography
  • Soil Mechanics
  • Operations Research
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE