Peculiarities of Methane Clathrate Hydrate Formation and Solid-State Deformation, Including Possible Superheating of Water Ice

Science  27 Sep 1996:
Vol. 273, Issue 5283, pp. 1843-1848
DOI: 10.1126/science.273.5283.1843


Slow, constant-volume heating of water ice plus methane gas mixtures forms methane clathrate hydrate by a progressive reaction that occurs at the nascent ice/liquid water interface. As this reaction proceeds, the rate of melting of metastable water ice may be suppressed to allow short-lived superheating of ice to at least 276 kelvin. Plastic flow properties measured on clathrate test specimens are significantly different from those of water ice; under nonhydrostatic stress, methane clathrate undergoes extensive strain hardening and a process of solid-state disproportionation or exsolution at conditions well within its conventional hydrostatic stability field.