georefid:2005-050526SEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContact2011-06-23T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=2005-050526<gco:CharacterString>Acoustic properties of sediments saturated with gas hydrate, free gas and water</gco:CharacterString>2003-01-01publication`georefid:2005-050526`

Gei, DavideIstituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, ItalyauthorCarcione, Jose M.authorEAGE (European Association of Geoscientists & Engineers), Houten, NetherlandspublisherdocumentHardcopyGeophysical Prospecting51 (2)141-157We obtain the wave velocities and quality factors of gas-hydrate-bearing sediments as a function of pore pressure, temperature, frequency and partial saturation. The model is based on a Biot-type three-phase theory that considers the existence of two solids (grains and gas hydrate) and a fluid mixture. Attenuation is described with the constant-Q model and viscodynamic functions to model the high-frequency behaviour. We apply a uniform gas/water mixing law that satisfies Wood's and Voigt's averages at low and high frequencies, respectively. The acoustic model is calibrated to agree with the patchy-saturation theory at high frequencies (White's model). Pressure effects are accounted by using an effective stress law for the dry-rock moduli and permeabilities. The dry-rock moduli of the sediment are calibrated with data from the Cascadia margin. Moreover, we calculate the depth of the bottom simulating reflector (BSR) below the sea floor as a function of sea-floor depth, geothermal gradient below the sea floor, and temperature at the sea floor.completedSedimentary petrologyApplied geophysicsacoustical propertiesaliphatic hydrocarbonsalkanesattenuationbottom-simulating reflectorsCascadia Basincontinental marginEast Pacificgas hydratesgeophysical methodsgeothermal gradientheat flowhydrocarbonsLeg 146marine methodsmethaneNorth PacificNortheast PacificOcean Drilling Programocean floorsODP Site 892organic compoundsPacific Oceanpore pressureQsaturated materialsseismic methodstemperatureviscositywater`urn:org.iodp:exp:146`

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urnlargerWorkCitationcampaignEnglishgeoscientificInformation-125.0709-125.070544.402644.4032