title: Anomalous waveforms observed in laboratory-formed gas hydrate-bearing and ice-bearing sediments.
abstract: Acoustic transmission measurements of compressional, P, and shear, S, wave velocities rely on correctly identifying the P- and S-body wave arrivals in the measured waveform. In cylindrical samples for which the sample is much longer than the acoustic wavelength, these body waves can be obscured by high-amplitude waveform features arriving just after the relatively small-amplitude P-body wave. In this study, a normal mode approach is used to analyze this type of waveform, observed in sediment containing gas hydrate or ice. This analysis extends an existing normal-mode waveform propagation theory by including the effects of the confining medium surrounding the sample, and provides guidelines for estimating S-wave velocities from waveforms containing multiple large-amplitude arrivals.
authors.affiliation: US Geological Survey, Denver Federal Center, Box 25046, MS-939, Denver, Colorado 80225, USA. mlee@usgs.gov
authors.forename: Myung W
authors.initials: MW
authors.lastname: Lee
authors.forename: William F
authors.initials: WF
authors.lastname: Waite
mesh_terms: D000162:Acoustics; D005740:Gases / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D007053:Ice; D008697:Methane / Q000737:chemistry; D008962:Models, Theoretical; D009792:Oceans and Seas; D012623:Seawater / Q000737:chemistry; D013018:Sound Spectrography
chemical_list: D005740:Gases; D007053:Ice; D008697:Methane