Collaborative Research: Seismic Characterization of a Gas Hydrate System in the Gulf of Mexico - A Novel Approach to Evaluate High-Resolution Wide-Angle Data

在美国地质勘探局、密西西比大学和能源部的一个联合项目中，从墨西哥湾天然气水合物环境中收集了单道地震和海底地震仪数据。初步结果表明，含水合物的泥底辟下的游离气，但缺乏底部模拟反射层（BSR）。PI建议进一步开发现有的地震层析成像代码，以自洽方式处理反射界面和转换横波。该代码将最初应用于一个有趣的天然气水合物的问题，从密西西比峡谷地区在墨西哥湾。这项新技术将用于了解：1）浅层水合物在海底下延伸多远？2)浅层水合物下是否存在游离气体？如果存在，是什么捕获了它？3)为什么没有BSR。将优化现有的三维数据，并将开发一种基于层析反演的三维PS-NMO方法。

In a joint project USGS, University of Mississippi and the DOE gathered single-channel seismic and ocean bottom seismometer data from the Gulf of Mexico gas hydrate environment. Initial results show free gas beneath a hydrate-bearing mud diapir but lacks a bottom-simulating reflector (BSR). The PIs propose to further develop an existing seismic tomography code to handle reflecting interfaces and converted shear waves in a self-consistent way. The code will be initially applied to an interesting gas hydrate problem from the Mississippi Canyon area in the Gulf of Mexico. The new technique will be used to learn: 1) how far does the shallow hydrates extend beneath the seafloor?, 2) does free gas exist beneath shallow hydrates and if so, what traps it?, 3) why is there no BSR present. The existing 3D data will be optimized and a method will be developed for 3D PS-NMO based on tomographic inversion.