南海北部神狐海域地质环境综合调查及科学意义

Scientific Implications and Preliminary Surveying Results of Geological and Physical Oceanography Environment in the Shenhu Area of the Northern South China Sea

在南海北部神狐海域水合物活跃区域开展了一次综合的海洋地质、物理海洋和生态环境调查,10个站位分布在水深1000~4000 m范围内的陆坡和深水盆地区域,是南海北部油气活跃的重要区域和天然气水合物试采区域.航次主要对10个海底站位进行了表层沉积物箱式和重力活塞柱状取样.针对天然气水合物试采区域,开展了一台"海燕"水下滑翔机的海洋物理环境连续走航剖面观测.利用海底地震仪在两个站位开展了连续海底地震和微振动观测.进行了站位的分层水体和沉积物样品中微生物学实验研究.初步航次结果展示了沉积物为黏土和软泥.站位和水下滑翔机走航观测提供了水体内海洋物理环境参数变化特征.海底地震仪观测展示了研究区天然地震活动和可能与水合物活动有关的微震动和短持续事件记录.微生物学实验揭示了沉积物中的微生物细菌群落特征.

A multi-disciplinary synthetic survey about marine geological,physical oceanography and biological environment was conducted in the Shenhu area bearing with the active gas hydrate in the northern South China Sea.Ten box corer and gravity-piston corer sites were located with the water depth of 1000 to 4000 m in the continental slope and deep basin area.It is the key area with the active oil and gas hydrate and is also the region of trial production of the gas hydrate in the northern South China Sea.The 10 sites coring designed by the cruise was conducted onboard with the surface box corer and gravity-piston corer sediment sampling.By deploying a"Haiyan"underwater glider,the underway measurement time-series profiles of the physical oceanography environment were obtained on the area of trial production of the gas hydrate in the Shenhu area.By using deployment and recovery of the two ocean bottom seismometers on two sites,time-series data of seafloor seismicity and microseisms and short duration events were obtained.Layering water sample from the CTD’s bottles and sediment samples from the box corers and gravity-piston corers are conducted by the microbiological experiment testing.The preliminary results of the cruise indicate that the sediment type is mainly clay and soft mud in the surveying area.The temperature and salinity parameter variations of the whole seawater from the CTD measurements and from the underwater glider are clearly shown.The seismicity activity and micro tremor possibly related to the gas hydrate is observed by the ocean bottom seismometers.The microbiological experiment shows the characteristic of the bacterial community abundance in the sediment.