Transformations in methane hydrates
January 1, 2000
Detailed study of pure methane hydrate in a diamond cell with in situ optical, Raman, and x-ray microprobe techniques reveals two previously unknown structures, structure II and structure H, at high pressures. The structure II methane hydrate at 250 MPa has a cubic unit cell of a = 17.158(2) A?? and volume V = 5051.3(13) A??3; structure H at 600 MPa has a hexagonal unit cell of a = 11.980(2) A??, c = 9.992(3) A??, and V = 1241.9(5) A??3. The compositions of these two investigated phases are still not known. With the effects of pressure and the presence of other gases in the structure, the structure II phase is likely to dominate over the known structure I methane hydrate within deep hydrate-bearing sediments underlying continental margins.
Citation Information
Publication Year | 2000 |
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Title | Transformations in methane hydrates |
DOI | 10.1073/pnas.250466497 |
Authors | I.-Ming Chou, A. Sharma, R. C. Burruss, J. Shu, Ho-kwang Mao, R.J. Hemley, A.F. Goncharov, L.A. Stern, S. H. Kirby |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Proceedings of the National Academy of Sciences of the United States of America |
Index ID | 70022139 |
Record Source | USGS Publications Warehouse |