Using Multiple Gravimeters to Test Conceptual Models of Subsurface Flow

University Of Arizona, Tucson AZ

Investigators

Abstract

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.