Probable patterns of gas flow and hydrate accretion at the base of the hydrate stability zone.
Probable patterns of gas flow and hydrate accretion at the base of the hydrate stability zone.
复制标题
水合物稳定带底部的气体流动和水合物增生的可能模式。
DOI：
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Ang Li
中科院分区：
文献类型：
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作者：
R. Davies;Jinxiu Yang;R. Hobbs;Ang Li
海洋天然气水合物是全球有机碳循环中最大的碳储集层，但对水合物在空间和时间上的生长规律知之甚少。毛里塔尼亚近海深水海洋天然气水合物倾斜基底的三维地震成像显示了垂直烟囱和连接的高和低地震反射振幅的泪滴状痕迹的非凡图案。高振幅的痕迹被解释为是由从水合物到游离含气沉积物的向下过渡造成的。它们的泪滴状表明，从烟囱中喷出的气体沿着水合物的底部向上倾斜流动。几何形状相似、振幅较低的痕迹可能是较早的流动，可能已经转化为水合物。对于这个地区，我们提出了一个模型的间歇性流动的气体的水合物的基础。活跃的流动被较早的、可能是水合物堵塞的烟囱状物阻挡，并可能被已经转化为水合物的流动横向限制，水合物形成的过程降低了沉积物的渗透性，并可能抑制随后的气体流动，导致出现气体流动和水合物增生的模式。
Marine gas hydrate is the largest carbon reservoir in the global organic carbon cycle, but there is limited knowledge of how hydrate is accreted in space and time. Three-dimensional seismic imaging of the dipping base of the deep-water marine gas hydrate from offshore Mauritania reveals extraordinary patterns of vertical chimneys and connected teardrop-shaped trails of both high and low seismic reflection amplitudes. The high-amplitude trails are interpreted as being caused by the downward transition from hydrate- to free gas–bearing sediments. Their teardrop form shows that gas emanating from the chimneys flowed updip along the base of the hydrate. The geometrically similar, lower-amplitude trails are possibly earlier flows that may have already converted to hydrate. For this area we propose a model of intermittent flow of gas to the base of the hydrate. Active flows were blocked updip by earlier, probably hydrate-clogged chimneys, and may have been laterally confined by flows that had already converted to hydrate that were in their path. The process of hydrate formation reduces sediment permeability and may suppress subsequent gas flows, resulting in the emergence of patterns of gas flow and hydrate accretion.
影响因子：
3.9
作者：
Chabert, Anne;Minshull, Tim A.;Sarkar, Sudipta
通讯作者：
Sarkar, Sudipta