Analysis of Deep Seafloor Arrivals Observed on NPAL04

Abstract

This report gives an overview of the analysis that was done on Deep Seafloor Arrivals since they were initially presented in Stephen et al (2009). All of the NPAL04/LOAPEX (North Pacific Acoustic Laboratory, 2004/ Long Range Ocean Acoustic Propagation Experiment) data on three ocean bottom seismometers (OBSs) at ~5,000m depth and the deepest element of the deep vertical line array (DVLA) at 4250m depth has been analyzed. A distinctive pattern of late arrivals was observed on the three OBSs for transmissions from T500 to T2300. The delays of these arrivals with respect to the parabolic equation predicted (PEP) path were the same for all ranges from 500 to 2300km, indicating that the delay was introduced near the receivers. At 500km range the same arrival was observed throughout the water column on the DVLA. We show that arrivals in this pattern converted from a PEP path to a bottom-diffracted surface reflected (BDSR) path at an off-geodesic seamount.

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Document Details

Document Type
Technical Report
Publication Date
Dec 03, 2012
Accession Number
ADA571996

Entities

People

  • Bruce M Howe
  • Ilya A. Udovydchenkov
  • James A. Mercer
  • John A. Colosi
  • Matthew A. Dzieciuch
  • Peter F. Worcester
  • Ralph Stephen
  • Rex K. Andrew
  • S. T. Bolmer

Organizations

  • Woods Hole Oceanographic Institution

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustics
  • Ambient Noise
  • Deep Oceans
  • Diffraction
  • Dynamic Range
  • Grids
  • Group Velocity
  • Measurement
  • Military Research
  • Oceanography
  • Oceans
  • Phase Velocity
  • Plastic Explosives
  • Ray Tracing
  • Seabed
  • Travel Time

Readers

  • Acoustical Oceanography.
  • Seismology