Vector Acoustics Measurements on the Washington Shelf in Coordination with the 2nd Joint Acoustics/Oceanography Experiment

Abstract

The Intensity Vector Autonomous Recorder system (IVAR) records four coherent channels of acoustic data continuously, one channel for acoustic pressure and three channels for acoustic acceleration from which acoustic velocity is obtained. This funding supports the deployment of IVAR during the 2nd Joint Acoustics/Oceanography Experiment to take place off coast of Washington and scheduled for June 2025, and post-experiment analysis of data. IVAR will be deployed at two locations during the experiment: (site A) on the shelf along the primary track of the planned active acoustic experiments, and (site B) on the slope at depth of 1000 m below a shipping channel. While at site A, measurements will be made in coordination with other teams on the Experiment, such as from active mid-frequency sources (500-2000 Hz). Also, estimates of the underlying sediment structure and stratigraphy will be made based on shipnoise as measured by having the research vessel pass directly overhead the IVAR sensor immediately after deployment and prior to recovery. Finally, measurements of Kauai Beacon will be possible at this site. While at site B, IVAR will be left behind for a long-term (8-week) deployment, with recovery at site B will be completed on separate cruise in September. In addition to optimal receptions of the Kauai Beacon, site B positions IVAR under a shipping lane to utilize the low-frequency harmonics from large ships to probe the structure of deep sediments and map the critical angle to identifying sediment-type provinces on the continental shelf.

Document Details

Document Type
DoD Grant Award
Publication Date
Jan 13, 2025
Source ID
N000142512123

Entities

People

  • Peter H. Dahl

Organizations

  • Office of Naval Research
  • United States Navy
  • University of Washington

Tags

Readers

  • Acoustical Oceanography.
  • Coastal and Marine Engineering/Sediment Transport/Hydraulic Engineering
  • Oceanography.