Elastic wave speeds and moduli in polycrystalline ice Ih, sI methane hydrate, and sII methane-ethane hydrate
Helgerud, M. B.
Waite, William F.
Kirby, S. H.
MetadataShow full item record
We used ultrasonic pulse transmission to measure compressional, P, and shear, S, wave speeds in laboratory-formed polycrystalline ice Ih, sI methane hydrate, and sII methane-ethane hydrate. From the wave speed's linear dependence on temperature and pressure and from the sample's calculated density, we derived expressions for bulk, shear, and compressional wave moduli and Poisson's ratio from −20 to −5°C and 22.4 to 32.8 MPa for ice Ih, −20 to 15°C and 30.5 to 97.7 MPa for sI methane hydrate, and −20 to 10°C and 30.5 to 91.6 MPa for sII methane-ethane hydrate. All three materials had comparable P and S wave speeds and decreasing shear wave speeds with increasing applied pressure. Each material also showed evidence of rapid intergranular bonding, with a corresponding increase in wave speed, in response to pauses in sample deformation. There were also key differences. Resistance to uniaxial compaction, indicated by the pressure required to compact initially porous samples, was significantly lower for ice Ih than for either hydrate. The ice Ih shear modulus decreased with increasing pressure, in contrast to the increase measured in both hydrates.
Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 114 (2009): B02212, doi:10.1029/2008JB006132.
Suggested CitationArticle: Helgerud, M. B., Waite, William F., Kirby, S. H., Nur, A., "Elastic wave speeds and moduli in polycrystalline ice Ih, sI methane hydrate, and sII methane-ethane hydrate", Journal of Geophysical Research 114 (2009): B02212, DOI:10.1029/2008JB006132, https://hdl.handle.net/1912/3597
Showing items related by title, author, creator and subject.
Correction to “Elastic wave speeds and moduli in polycrystalline ice Ih, sI methane hydrate, and sII methane-ethane hydrate” Helgerud, M. B.; Waite, William F.; Kirby, S. H.; Nur, A. (American Geophysical Union, 2009-04-10)
Pohlman, John W.; Bauer, James E.; Canuel, Elizabeth A.; Grabowski, Kenneth S.; Knies, D. L.; Mitchell, C. S.; Whiticar, M. J.; Coffin, Richard B. (2009-06-16)Fossil methane from the large and dynamic marine gas hydrate reservoir has the potential to influence oceanic and atmospheric carbon pools. However, natural radiocarbon (14C) measurements of gas hydrate methane have been ...
Ruppel, Carolyn D.; Kessler, John D. (John Wiley & Sons, 2017-02-08)Gas hydrate, a frozen, naturally-occurring, and highly-concentrated form of methane, sequesters significant carbon in the global system and is stable only over a range of low-temperature and moderate-pressure conditions. ...