Through manufacturing and geophysically characterising the properties and distribution of a range of synthetic gas hydrate morphologies in a range of sediments in the laboratory, protocols will be established for geophysically logging natural sediment-hydrate core preserved in pressure chambers on board ship. Based on pressure cycling, geophysical behaviour responses will be determined during the start of dissociation and formation. On this basis the investigators then propose to develop protocols to characterise and classify hydrates sampled during ODP Leg 204, significantly improving our understanding of the nature and behaviour of these sediments. This new knowledge will enhance geophysical survey data, better constrain estimates of in-situ hydrates and improve the evaluation of hydrate destabilisation on methan release and slope stability.