RAPID: Investigating spatiotemporal groundwater variations in the Wasatch Front using geophysical methods

University Of Utah, Salt Lake City UT

Investigators

Abstract

This RAPID project focuses on geophysical data collection to capture the runoff and groundwater flows from the anomalous 2023 Spring melt in Northern Utah. This year’s snow depth maximum is greater than 200% of the historical average and comes after more than 20 years of megadrought conditions for the region. The goal is to test the ability of geophysical techniques to capture the physical hydrological processes to improve estimates of the water budget of the Great Salt Lake (GSL) and the ecosystems of its wetlands. Research in the last decade demonstrates that Wasatch Mountain snowpack melts in the spring and is split between soil moisture and groundwater before becoming available as surface water. Geophysical observations can provide independent constraints to the hydrological system. This project aims to demonstrate that the geophysics data are uniquely suited to quantify the amount and time scales of water storage in seasonal snow, soil moisture, groundwater, and ultimately surface water storage in reservoirs and the Great Salt Lake. This project will contribute to a better understanding of the path that water takes from the mountains to the valley and may potentially help to guide decision/policy making for water use and consumption. The project supports undergraduates participating in data collection and analysis. The data collected through this experiment will be archived and made openly available through the SAGE-GAGE facility and the University of Utah data repository. The RAPID project will yield new continuous seismic and episodic gravity and electronic resistivity tomography (ERT) observations at a high spatial resolution that will be used to determine the advantages and limitations of these geophysical techniques for investigating the transport and storage of water in the Wasatch Mountain/Salt Lake Valley hydrological system. Monitoring subsurface seismic velocity changes will allow investigations of groundwater and soil moisture variation. Using gravity along with geodetic surface deformation modeling to determine changes in water mass over different but hydrologically connected (and physically proximal) regimes is a new and potentially valuable technique to monitor water mass transport from the mountains to the valley. ERT monitoring can be used to detect the migration of the fresh/saline interface at the edge of the Great Salt Lake as the snowmelt moves into the valley. By leveraging the complementary sensitivity of the geophysics observations, the proposed project will advance the spatial and temporal resolution of the measurements in the Wasatch Mountains and the Salt Lake Valley. This project is supported by the Geophysics Program, the Hydrological Sciences Program, and the Division of Earth Sciences. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.