Using Multiple Gravimeters to Test Conceptual Models of Subsurface Flow

地下水水文学中的两个基本问题是需要定位和追踪地下水，以及确定有助于模型预测的地下水属性。这些需要导致了各种数据收集和解释方法的发展。在所有这些方法中，只有一次时间推移重力监测提供了对储存中的水质量变化的直接测量。重力仪的最新进展使收集空间分布的、时间上连续的重力数据成为可能。要充分利用这些仪器提供的数据，就需要开发新的水文/重力耦合建模方法。在该项目下，将对在水储存和回收设施收集的大量先前存在的重力数据集进行建模，以开发和改进水文重力建模方法。然后，将在这些分析的基础上进行空间上广泛的数据收集工作，以完善我们对储存和回收设施下地下水运动的解释。拟议的研究处于将地球物理数据与模型相结合的持续发展的前沿，并在需要跟踪和模拟地下流体运动的领域有广泛的应用，如水文学，但也包括石油和天然气储层监测、碳封存和火山监测。该项目将展示一种新的超导重力仪，这是现有的最精确的仪器，可以在不影响仪器漂移的情况下移动，从而允许使用这种先进的仪器进行移动监测。这项拟议的研究特别支持学生培训，以发展在美国境内使用这些仪器的专业知识。

Two fundamental problems in groundwater hydrology are the need to locate and track subsurface water, and to identify subsurface properties that facilitate model predictions. These needs have led to the development of a wide range of data collection and interpretation methods. Among all of these methods, only one-time lapse gravity monitoring provides direct measurements of changes in the mass of water in storage. Recent advances in gravimeters allow for collection of spatially distributed, temporally continuous gravity data. To make full use of the data that these instruments provide requires the development of new approaches to coupled hydrologic/gravity modeling. Under this project, an extensive pre-existing gravity data set, collected at a water storage and recovery facility, will be modeled to develop and improve hydrogravimetric modeling approaches. Then, a spatially extensive data collection effort will be conducted based on these analyses to refine our interpretations of subsurface water movement beneath the storage and recovery facility. The proposed research is at the forefront of the continuing evolution of integrating geophysical data with models and has wide applications in fields needing to tracking and modeling subsurface fluid movement, such as hydrology, but also including oil and gas reservoir monitoring, carbon sequestration, and volcano monitoring. The project will demonstrate that a new, superconducting gravimeter, which is the most precise instrument in existence, can be moved without affecting instrument drift, allowing for mobile monitoring with this advanced instrument. The proposed research supports student training specifically to develop the expertise in the use of these instruments within the United States.