울릉분지 가스수화물 및 해저사면사태 규명을 위한 시추

Abstract

Submarine slope failure and derived sediment gravity flows are recognized as a major sedimentary process in basins worldwide. Their large failure volumes and long-runout distances pose significant tsunami hazard for offshore and coastal facilities, and thus it is important to understand the mechanisms and processes involved in the initiation of slope failure. One hypothesis currently being debated is that sea level fluctuations and ocean bottom temperature changes can cause gas hydrate dissociation and/or dissolution and/or gas exsolution and expansion leading to submarine slope failure. However, evidence that propagation in seafloor sediments of pressure and thermal perturbations associated with climate change induce slope instability is lacking, and more importantly there has not been a dedicated study to investigate these feedbacks. To move forward in our understanding of the roles of climate, sedimentation patterns, geomechanical properties of gas-hydrate bearing sediments and slope stability, we propose to acquire an expanded Quaternary record of mass-wasting activity, gas emissions, climatic/paeloceanographic proxies and physical properties to better constrain the gas hydrate-slope failure system. The Ulleung Basin, situated between the Korean peninsula and the Japanese archipelago, is an optimal study region because: (1) the high abundance of gas hydrates, particularly at the southern end of the basin (2) moreilities, and thus it is important to understand the mechanisms and processes involved in the initiation of slope failure. One hypothesis currently being debated is that sea level fluctuations and ocean bottom temperature changes can cause gas hydrate dissociation and/or dissolution and/or gas exsolution and expansion leading to submarine slope failure. However, evidence that propagation in seafloor sediments of pressure and thermal perturbations associated with climate change induce slope instability is lacking, and more importantly there has not been a dedicated study to investigate these feedbacks. To move forward in our understanding of the roles of climate, sedimentation patterns, geomechanical properties of gas-hydrate bearing sediments and slope stability, we propose to acquire an expanded Quaternary record of mass-wasting activity, gas emissions, climatic/paeloceanographic proxies and physical properties to better constrain the gas hydrate-slope failure system. The Ulleung Basin, situated between the Korean peninsula and the Japanese archipelago, is an optimal study region because: (1) the high abundance of gas hydrates, particularly at the southern end of the basin (2) more