01200nas a2200157   4500000000100000000000100001008004100002100001900043700001600062700001200078245009500090300001200185490000700197520082400204020001401028       2005                            d1 aC.R.I. Clayton1 aJ.A. Priest1 aAI Best00aThe effects of disseminated methane hydrate on the dynamic stiffness and damping of a sand  a423-4340 v553 aMethane hydrates are ice-like compounds that can exist only under restricted thermobaric conditions, at low temperatures or under high ambient pressure. They are important because of their potential contributions as a future source of energy, to global warming, and as a possible trigger for long run-out submarine slope instability. This paper describes laboratory experiments to synthesise disseminated methane hydrates and to characterise them under small-strain dynamic loading in the resonant column apparatus. The effects of depositing varying quantities of methane hydrate within a sand are investigated by reference to their shear and bulk modulus, and damping, over a range of isotropic effective stress. Results are compared with those obtained on the same sand without hydrate bonding and after dissociation.  a0016-8505