title: Bayesian environmental inversion of airgun modal dispersion using a single hydrophone in the Chukchi Sea.
abstract: This paper presents estimated water-column and seabed parameters and uncertainties for a shallow-water site in the Chukchi Sea, Alaska, from trans-dimensional Bayesian inversion of the dispersion of water-column acoustic modes. Pulse waveforms were recorded at a single ocean-bottom hydrophone from a small, ship-towed airgun array during a seismic survey. A warping dispersion time-frequency analysis is used to extract relative mode arrival times as a function of frequency for source-receiver ranges of 3 and 4 km which are inverted for the water sound-speed profile (SSP) and subbottom geoacoustic properties. The SSP is modeled using an unknown number of sound-speed/depth nodes. The subbottom is modeled using an unknown number of homogeneous layers with unknown thickness, sound speed, and density, overlying a halfspace. A reversible-jump Markov-chain Monte Carlo algorithm samples the model parameterization in terms of the number of water-column nodes and subbottom interfaces that can be resolved by the data. The estimated SSP agrees well with a measured profile, and seafloor sound speed is consistent with an independent headwave arrival-time analysis. Environmental properties are required to model sound propagation in the Chukchi Sea for estimating sound exposure levels and environmental research associated with marine mammal localization.
authors.affiliation: School of Earth and Ocean Sciences, University of Victoria, 3800 Finnerty Road, Suite A405, Victoria, British Columbia V8P 5C2, Canada.
authors.forename: Graham A
authors.initials: GA
authors.lastname: Warner
authors.affiliation: School of Earth and Ocean Sciences, University of Victoria, 3800 Finnerty Road, Suite A405, Victoria, British Columbia V8P 5C2, Canada.
authors.forename: Stan E
authors.initials: SE
authors.lastname: Dosso
authors.affiliation: School of Earth and Ocean Sciences, University of Victoria, 3800 Finnerty Road, Suite A405, Victoria, British Columbia V8P 5C2, Canada.
authors.forename: Jan
authors.initials: J
authors.lastname: Dettmer
authors.affiliation: JASCO Applied Sciences, 2305-4464 Markham Street, Victoria, British Columbia V8Z 7X8, Canada.
authors.forename: David E
authors.initials: DE
authors.lastname: Hannay
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000465:Algorithms; D001499:Bayes Theorem; D003198:Computer Simulation; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019015:Geologic Sediments; D008390:Markov Chains; D008962:Models, Theoretical; D009010:Monte Carlo Method; D009038:Motion; D009792:Oceans and Seas; D011312:Pressure; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D013018:Sound Spectrography; D013997:Time Factors; D014160:Transducers, Pressure; D014867:Water
chemical_list: D014867:Water