URI Field Work in the 2021 Seabed Characterization Experiment
Abstract
Our previous work over the last few years has been focused on understanding the frequency and depth dependence of the bottom compressional and shear wave speed and attenuation. Often, the elastic properties (shear effects) can become important and control the bottom loss as a function of angle and frequency. Our previous investigations have also indicated that water-borne acoustic arrival properties such as their Airy Phase are sensitive to sediment shear properties. We have been developing new inversion schemes for the estimation of shear wave properties. Recently, we were successful in designing, assembling and testing of a new Interface Wave Sediment Profiler (iWaSP) to estimate shear properties as function of depth and position. This device was funded through the DURIP program. We were successful in deploying this system (for a very short duration) during the ONR funded Seabed Characterization Experiment (SBCEX) 2017. This new system will be integrated into our recently acquired Ocean Bottom Seismometers (OBX); acquired under a separate DURIP grant in this study. This proposal is closely coordinated with the white paper entitled Seabed Characterization within a Dynamic Ocean submitted by David Knobles which proposes the next seabed characterizationexperiments in 2021. These experiments will provide additional data to address the objectives of this study. The scientific objectives of URIs acoustic tasks in the Seabed Characterization Experiment 2021 are to study the acoustic physics in laterally heterogeneous fine-grained sediments, and to develop and validate seabed geoacoustic inversion methods. Our specific objective is to measure interface waves and estimate shear properties of the sediments using an inversion scheme. Our main experimental assets include the Interface Wave Sediment Profiler (iWaSP) to generate interface waves, 3-axis Ocean Bottom Seismometers (OBX), and atetrahedral hydrophone array to measure particle velocities in the water column. The description of this effort can be located in R2 for Ocean Wrfghtg Env Applied Research in PE 0602435N.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 20, 2020
- Source ID
- N000142012557
Entities
People
- James M. L. Miller
Organizations
- Office of Naval Research
- United States Navy
- University of Rhode Island