Geophysical imaging of shallow degassing in a Yellowstone hydrothermal system
Geophysical imaging of shallow degassing in a Yellowstone hydrothermal system
复制标题
黄石热液系统浅层脱气的地球物理成像
DOI：
10.1002/2016gl071306
复制
发表时间：
2016
影响因子：
5.2
通讯作者：
K. Sims
中科院分区：
文献类型：
--
作者：
S. Pasquet;W. Holbrook;B. Carr;K. Sims
黄石高原火山场拥有10,000多个热特征，是世界上最大的活跃大陆热液系统，但人们对连接热液储集层和地表特征的浅“管道”系统知之甚少。本文介绍了黄石公园浅层热液脱气的地球物理研究结果。我们测量了来自折射资料的电阻率、纵波速度和面波分析的横波速度，以成像15-30 m的浅层热液脱气。我们发现，电阻率有助于识别流体路径，泊松比对饱和度变化表现出很好的敏感性，突出了含气饱和区和局部地下水位。岩石物理模拟预测的孔隙度和饱和度为估计流体相分离深度和了解热液系统的结构提供了重要的见解。最后，我们的结果表明，泊松比可以有效地区分水热系统中的含气和含水饱和区。
The Yellowstone Plateau Volcanic Field, which hosts over 10,000 thermal features, is the world's largest active continental hydrothermal system, yet very little is known about the shallow “plumbing” system connecting hydrothermal reservoirs to surface features. Here we present the results of geophysical investigations of shallow hydrothermal degassing in Yellowstone. We measured electrical resistivity, compressional‐wave velocity from refraction data, and shear wave velocity from surface‐wave analysis to image shallow hydrothermal degassing to depths of 15–30 m. We find that resistivity helps identify fluid pathways and that Poisson's ratio shows good sensitivity to saturation variations, highlighting gas‐saturated areas and the local water table. Porosity and saturation predicted from rock physics modeling provide critical insight to estimate the fluid phase separation depth and understand the structure of hydrothermal systems. Finally, our results show that Poisson's ratio can effectively discriminate gas‐ from water‐saturated zones in hydrothermal systems.