Physical controls on methane ebullition from reservoirs and lakes
Physical controls on methane ebullition from reservoirs and lakes
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DOI：
10.2113/9.2.167
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发表时间：
2003-05-01
影响因子：
0.9
通讯作者：
Jewell, PW
中科院分区：
文献类型：
--
作者：
Joyce, J;Jewell, PW
了解水生沉积物中甲烷产生和通量的性质和程度具有重要的地球化学，岩土工程和全球气候变化的影响。量化这些过程是困难的，因为浅层沉积物中的甲烷通量大部分是通过沸腾（起泡）发生的。直接观察气泡的形成是不可能的，并且气泡是间歇性的，取决于许多因素。虽然以前的研究已将甲烷通量与地表风强度相关联，但对巴拿马加通湖和波多黎各的洛伊扎湖的详细研究表明，甲烷通量与底流引起的沉积物中的剪切应力关系更为密切。底层流又是风、内部压力梯度和湖泊水深的复杂函数。一个简单的物理模型的底部电流和沉积物在这些湖泊表明，大多数甲烷沸腾起源于上部10-20厘米的沉积物柱。我们的数据证实了以前的研究表明，沸腾甲烷通量是次要的水深约5米。
Understanding the nature and extent of methane production and flux in aquatic sediments has important geochemical, geotechnical, and global climate change implications. Quantifying these processes is difficult, because much of the methane flux in shallow sediments occurs via ebullition (bubbling). Direct observation of bubble formation is not possible, and bubbling is episodic and dependent upon a number of factors. Whereas previous studies have correlated methane flux with surface wind intensity, detailed study of Lake Gatun in Panama and Lago Loiza in Puerto Rico suggest that methane flux is more closely correlated with the shear stress in sediments caused by bottom currents. Bottom currents in turn are a complex function of wind, internal pressure gradients, and lake bathymetry. A simple physical model of bottom currents and sediments in these lakes suggests that most methane ebullition originated from the upper 10-20 cm of the sediment column. Our data reaffirm previous studies showing that ebullitive methane flux is minor in water deeper than similar to5 m.