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Chris Bassett Senior Mechanical Engineer cbassett@uw.edu Phone 206-543-1263 |
Research Interests
Passive noise studies, acoustic scattering, sea ice, marine renewable energy, fisheries acoustics, anthropogenic noise
Biosketch
Chris applies passive and active acoustic techniques to a variety of underwater applications. Some of his previous and ongoing studies include fisheries acoustics; high-frequency scattering from sea ice, crude oil, and physical oceanographic processes; measurements of anthropogenic noise; and ambient noise studies.
Education
B.S. Mechanical Engineering, University of Minnesota, 2007
M.S. Mechanical Engineering, University of Washington, 2010
Ph.D. Mechanical Engineering, University of Washington, 2013
Videos
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Turbulence Generated by Tides in the Canal de Chacao, Chile At a proposed tidal energy conversion site in southern Chile, APL-UW researchers are measuring the magnitude and scales of turbulence, both to aid in the design of turbines for the site and to understand the fundamental dynamics of flows through the channel. |
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7 Mar 2013
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Principal Investigator Jim Thomson chronicled all phases of the Chilean experiment through posts to the New York Times 'Scientist at Work' blog. |
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Sound Sounds: Listening to the Undersea Noise in Puget Sound Doctoral student researcher Chris Bassett is analyzing a long time series of ambient noise data from Puget Sound. Vessel traffic is the most significant noise source, but breaking waves, precipitation, biology, and sediment moving on the seabed are other common underwater noise sources. The research is being pursued in conjunction with a program to assess the environmental impacts from a tidal energy conversion system placed on the seafloor. |
13 Mar 2012
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Publications |
2000-present and while at APL-UW |
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Classification of broadband target spectra in the mesopelagic using physics-informed machine learning Cotter, E., C. Bassett, and A. Lavery, "Classification of broadband target spectra in the mesopelagic using physics-informed machine learning," J. Acoust. Soc. Am., 149, 3889-3901, doi:10.1121/10.0005114, 2021. |
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1 Jun 2021 ![]() |
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Broadband echosounders measure the scattering response of an organism over a range of frequencies. When compared with acoustic scattering models, this response can provide insight into the type of organism measured. Here, we train the k-Nearest Neighbors algorithm using scattering models and use it to group target spectra (2540 kHz) measured in the mesopelagic near the New England continental shelf break. Compared to an unsupervised approach, this creates groupings defined by their scattering physics and does not require significant tuning. The model classifies human-annotated target spectra as gas-bearing organisms (at, below, or above resonance) or fluid-like organisms with a weighted F1-score of 0.90. Class-specific F1-scores varied the F1-score exceeded 0.89 for all gas-bearing organisms, while fluid-like organisms were classified with an F1-score of 0.73. Analysis of classified target spectra provides insight into the size and distribution of organisms in the mesopelagic and allows for the assessment of assumptions used to calculate organism abundance. Organisms with resonance peaks between 25 and 40 kHz account for 43% of detections, but a disproportionately high fraction of volume backscatter. Results suggest gas bearing organisms account for 98.9% of volume backscattering concurrently measured using a 38 kHz shipboard echosounder between 200 and 800 m depth. |
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Comparison of mesopelagic organism abundance estimates using in situ target strength measurements and echo-counting techniques Cotter, E., C. Bassett, and A. Lavery, "Comparison of mesopelagic organism abundance estimates using in situ target strength measurements and echo-counting techniques," J. Acoust. Soc. Am. EL, 1, 040801, doi:10.1121/10.0003940, 2021. |
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2 Apr 2021 ![]() |
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Recent studies using acoustic techniques suggest that the biomass of mesopelagic fishes may be an order of magnitude higher than previously estimated from trawls. However, there is uncertainty surrounding these estimates, which are derived from shipboard echosounder measurements using necessary, but poorly constrained, assumptions. Here, an echosounder is used to measure individual target strengths at depth. These measurements are used to infer mesopelagic organism density through echo-counting. Measured target strengths are used to estimate organism density by inverting shipboard echosounder measurements. The two sampling methods agree well, but highlight the importance of accurate target strength measurements. |
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Risk to marine animals from underwater noise generated by marine renewable energy devices Polagye, B., and C. Bassett, "Risk to marine animals from underwater noise generated by marine renewable energy devices," in OES-Environmental 2020 State of the Science Report: Environmental Effects of Marine Renewable Energy Development Around the World, A.E. Copping and L.G. Hemery, eds., 67-85, doi:10.2172/1633082 (Ocean Energy Systems, 2020). |
30 Sep 2020 ![]() |
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In The News
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Oscilla Power, Univ. of Wash. and others share $25M federal grant to spur wave energy efforts GeekWire, Lisa Stiffler The UW, in partnership with Integral Consulting, will study the underwater noise being created by wave energy converters that are being tested at the PacWave South facility on the Oregon Coast. The information will be helpful to wave energy entrepreneurs and regulating agencies working to make sure the devices don’t harm marine life. |
27 Jan 2022
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Sounds of the sea: Stones clanging Inside Science, Joel N. Shurkin Tide-borne pebbles on the seabed can drown out other ocean noises. According to research by Christopher Bassett and colleagues published in the Journal of Geophysical Research, the noise from gravel on the seabed is significant to the overall undersea soundscape. |
21 May 2013
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Noisy ships, ferries create racket below Puget Sound The Seattle Times, Craig Welch Recent work by University of Washington researchers shows noise in some Puget Sound shipping channels regularly meets or exceeds levels the federal government suggests may be harmful to marine life. |
3 Jan 2013
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