内孤立波对南海水合物试采区海底面稳定性影响研究

南海内孤立波发育，其传输的能量、强度、发生频率，居世界上五大内孤立波发育海区之首。南海水合物试采区，位于北部陆坡神狐海域，内孤立波在该区发生浅化破碎，将大量能量传递给海底，造成温度与压力异常，导致海底面水合物分解。内孤立波作用过程对海底面稳定性影响，亟待研究解答。本项目基于现场原位长期观测，研究内孤立波作用过程中，海底面压力变化、浅层沉积物孔隙水压力累积及温度变化、水合物分解泄漏、海底面沉降变形滑动及海底沉积物侵蚀再悬浮。预期成果，定量揭示内孤立波对水合物试采区所处的南海北部陆坡海底沉积物影响，及对水合物分解泄漏的影响；建立水合物试采区内孤立波引起的海底面沉降变形滑动量预测方法，及沉积物侵蚀再悬浮量预测方法，为水合物试采工程安全保障提供科学依据。本项目综合考虑内孤立波作用与水合物分解，利用自主研发集成的设备，进行南海水合物试采区海底面稳定预测研究，具有显著的创新性。

The South China Sea is one of five internal solitary wave zones with the biggest energy, strength and frequency. The gas hydrate production area in the South China Sea is located at the Shenhu area, north continental slope, where the internal solitary waves break. The abnormity of temperature and pressure caused by the internal solitary waves may lead to the dissociation of the gas hydrate. It is unclear how the internal solitary waves affect the seafloor instability in the hydrate production area. Based on the in-situ observation, this project is aimed to study the pressure and temperature change at the seafloor, pore water pressure accumulation, dissociation of the gas hydrate, seafloor deformation, sediment erosion and resuspension. The research goal is to answer the unresolved questions, namely the influence of the internal solitary waves on the stability of continental slope, and the influence of the internal solitary waves on the gas hydrate dissociation. The research will also serve the safety of hydrate production by stablishing a quantitative prediction and evaluation method of seafloor instability. This project is feature by the in-situ observation, which is taken to research the influence of the internal solitary wave and gas hydrate on the seafloor instability.