Natural gas hydrates are clathrates, a class of compounds in which an expanded crystalline structure of water forms about a host gas molecule. Gas hydrates found in the marine environment are generally composed of methane combined with varying amounts of other hydrocarbon gases such as ethane and propane. The occurrence of gas hydrates within the seafloor may significantly alter elastic properties of the bulk sediment resulting in the possibility of identifying hydrated sediments by acoustic remote sensing. The Biot poroelastic theory [Stoll, 1977] is used to gain insight into the acoustic response of an unconsolidated marine sediment with included gas hydrates. Available geoacoustic parameter measurements for hydrated sediments, and their constituents, are of limited extent. Therefore, physical sediment model parameters are estimated both theoretically and empirically for varying concentrations of gas hydrate saturation within the sediment. These geoacoustic modeling results indicate that discernible returns for a hydrated marine sediment should be present under certain conditions.
