中文摘要：

使用重力取样器、渔网、深潜器等手段已经在海底及以下浅表层区域采获天然气水合物样品。但关于浅表层水合物的发育机制、分布规律及与海底地形的关系等问题还缺乏基本认识。根据2006年鄂霍次克海天然气水合物调查航次的调查数据，介绍了浅表层天然气水合物区的海底地形特征。萨哈林东北陆坡区，特别是中、下陆坡区发育大量海底凸起，这些凸起一般呈不对称的丘形，宽几百米，高几十米。不同于海底沙波、沙脊，海底凸起为孤立海底地形，在南北方向上并不连续。海底凸起和浅表层天然气水合物的发育密切相关。在海底剖面仪测量结果剖面上清楚地显示古陆坡凸起的发育。普遍地，现今海底陆坡凸起的幅度要小于古陆坡凸起的幅度，个别地方古、今陆坡凸起的形态有所变化，但大部分古、今陆坡凸起是一一对应的，基本形态没有根本变化。在萨哈林陆坡地区存在两个方向的挤压应力场，分别是由德鲁根盆地向萨哈林陆坡方向的挤压应力场、萨哈林陆坡沿萨哈林走滑断裂向南的挤压应力场。海底陆坡凸起是这两大应力场复合作用的结果。浊反射区中的游离气是底辟构造中的超高压多相物质向上迁移形成的。浊反射区上方对应的海底凸起应该是宏观构造挤压和局部底辟发育叠合的结果。浊反射区上方的海底凸起，在形态等方面应该和其他仅由挤压构造原因形成的凸起有所区别，比如顶部发育裂口等。在底辟构造中，由于游离气体的向上迁移，在整个水合物稳定域中从下到上，直至海底都可能形成水合物，从而使我们有机会使用重力采样器这样的设备也能采获天然气水合物样品。

英文摘要：

Shallow gas hydrates had already been retrieved sible machine on the sea floor and in the sediment near to by gravity corer, busyness fishing net, and submersible machine on the sea floor and in the sediment near to the sea floor. However the formation mechanism of shallow gas hydrate, distribution of shallow gas hydrate, and also the relationship between shallow gas hydrate and sea floor topography still remain unclear. Based on the side scan sonar and sub-bottom profile data from 2006 gas hydrate cruise in the area of Okhotsk Sea, the paper found that shallow gas hydrates closely related to the dome structures. The dome structures were commonly found on the slope, especially along the Middle and Lower Sakhalin Slope which were about several hundred meters wide and several ten meters high. Different from sea floor sand waves and sand ridges, the dome structures were isolated structures but with a slightly longer andlower wing than that of the upper wing. Sub-bottom profile recorder also showed that buried dome structures also very well developed on the slope beneath a 30 cm modern sediment layer. A joint compress stress field from Deryugin basin to the Sakhalin Slope and also from north Sakhalin Slope to the South Sakhalin Slope along the strike slip fault along Sakhalin Slope was the main cause of the formation of the dome structures, and also the main cause of the diapir structures among the dome structures. Acoustic turbidity beneath the diapir structures clearly show the migration of free gases from deep to the gas hydrate stability zone and to the sea water body from the mini crater on top of the dome structure. Gas hydrates were formed due to the availability of free gas within the diapir structures from the bottom of gas hydrate stability zone up to the sea floor.