HR: 0800h
AN: T41B-1185    [Abstracts]
TI: High pressure NMR spectroscopy of clathrate hydrates
AU: * Okuchi, T
EM: t.okuchi@gl.ciw.edu
AF: Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015 United States
AU: * Okuchi, T
EM: t.okuchi@gl.ciw.edu
AF: Graduate School of Environmental Sciences, Nagoya University, Nagoya, 464-8601 Japan
AU: Hemley, R J
EM: r.hemley@gl.ciw.edu
AF: Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015 United States
AU: Mao, H
EM: h.mao@gl.ciw.edu
AF: Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015 United States
AB: Clathrate hydrates are molecular compounds consisting of water and non-polar gas molecules that are only stable at high pressures. Methane hydrate, the most common of these clathrates, is considered as an important constituent "mineral" of icy satellites. Its existence in the earth's hydrosphere, including seafloor sediments, has attracted much attention as an energy resource. The material undergoes phase transformations to denser clathrates at high pressure ($>$1 GPa). The origin of the stability of the high-pressure forms (i.e., filled ices) of these materials is of great interest. To address this question, we are conducting nuclear magnetic resonance (NMR) measurements at high pressures in a diamond anvil cell (Okuchi, 2004; Okuchi et al., 2004). NMR is a very sensitive method to monitor the state of hydrogen bonding. We can also obtain information on local dynamics of molecules by NMR. We will present our results and discuss the nature of intermolecular interactions in clathrate hydrates at high pressure relevant to planetary interiors.
DE: 5724 Interiors (8147)
DE: 6045 Physics and chemistry of materials
DE: 3924 High-pressure behavior
DE: 3929 NMR, Mossbauer spectroscopy, and other magnetic techniques
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting