Preliminary Results on Seamount and Continental Slope Reflection Enhancement of Shipping Noise

Abstract

Measurements of ambient noise levels made during a time period when a supertanker passed the observation site clearly show such vessels to be a strong acoustic source. The tonals associated with the propeller blade rate and its frequency harmonics were clearly observed on single, omni-directional hydrophones for ranges out to 240 nautical miles. The received signals from the radiated noise from this vessel increased in level by as much as 10 dB when it was in the vicinity of a seamount and the continental slope, suggesting a reflection enhancement. The magnitude of this observed reflection enhancement varies inversely with hydrophone depth, being the largest for the shallowest depth.

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Document Details

Document Type
Technical Report
Publication Date
Nov 07, 1975
Accession Number
ADA023476

Entities

People

  • G. B. Morris

Organizations

  • Scripps Institution of Oceanography

Tags

Communities of Interest

  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustic Signals
  • Ambient Noise
  • Blades
  • California
  • Classification
  • Continental Slopes
  • Convergence Zones (Sonar)
  • Governments
  • Measurement
  • Military Research
  • Noise
  • Oceanography
  • Propeller Blades
  • Radiated Noise
  • Radiation Patterns
  • Reflection

Readers

  • Acoustical Oceanography.
  • Mathematics or Statistics
  • Oceanography.