Qualifying Exam:Valeriia Sobolevskaia
Date: Wednesday, May 25th, 2022
Time: 3:00 p.m.
Zoom Link: https://riceuniversity.zoom.us/j/3609157539?pwd=OTVjcjJ1N2FBZkNueHcrRStCTjJCUT09
Meeting ID: 360 915 7539
Monitoring of the Gulf coast aquifer system: an alternative geophysical perspective
Freshwater is one of the key natural resources critical for human survival. Groundwater provides about a third of all freshwater consumed globally, however, this number will likely grow as surface freshwater resources become less reliable due to climatic and anthropogenic impacts. About a third of the world’s largest aquifer systems are already in distress and the key underlying reasons for this are man-made. Hence, there is an urgent need in the development of regulations and systematic, long-term, large-scale monitoring and modelling techniques to protect and preserve clean water supply and ensure its sustainable development. In this proposal, I will address the question of aquifer monitoring and modeling using geophysical tools. I will focus on seismic data that allow to monitor aquifer behavior locally and on regional scale. With the help of collected field data, I will attempt to create and calibrate a model that can predict a potential response of the Gulf coast aquifer system to forthcoming climate events and human activities. If successful, the proposed monitoring technique together with a rock physics model can become an efficient tool for aquifer management that will help to address water supply concerns.
Understanding matric potential effect using seismic velocity
Partial saturation is an inherent feature of near-surface regions that gives rise to matric potential effect, i.e., negative pore water pressure due to capillary and adsorptive forces. Matric potential plays crucial role in understanding soil biodynamics and elastic response, yet it is often ignored and remains understudied. One of the main reasons behind that is challenges associated with its measurement. In this proposal I suggest using seismic method to monitor temporal and spatial variations in soil moisture and matric potential and characterize their interdependence. Using data from a controlled lab experiment I propose to test a theoretical model that captures physical processes in partially saturated rocks and then apply the same method in a small-scale field experiment. If successful, this approach will provide an alternative method to obtain spatial matric potential distribution with improved accuracy and resolution.