Integrating Stable Isotope Variation and Seismic Field Perturbations to Understand Recharge to a Fractured-Basalt Aquifer System
Additional Funding Sources
This project is supported by a 2019-2020 STEM Undergraduate Research Grant from the Higher Education Research Council.
Abstract
A multi-component project is being conducted for examination of groundwater recharge to the fractured basalt and interbedded sediment aquifer system of the South Fork Palouse River Basin. Isotope analysis (δO18 and δH2) of snowmelt and groundwater is being used to identify areas of fast and slow groundwater recharge (differences in hydraulic conductivity) along the eastern margin of the basin where recharge can enter the aquifer system through a sedimentary unit at the mountain-front interface. Identification of the variation of hydraulic conductivity and recharge pathways will assist in quantifying groundwater recharge by complementing a second project that is installing seismic stations along the mountain-front interface for monitoring groundwater flux. A velocity analysis of low frequency perturbations in the ambient seismic field at each station will allow us to identify changes in sedimentary unit water levels from which we can calculate a flux of groundwater passing through the recharge zone.
Integrating Stable Isotope Variation and Seismic Field Perturbations to Understand Recharge to a Fractured-Basalt Aquifer System
A multi-component project is being conducted for examination of groundwater recharge to the fractured basalt and interbedded sediment aquifer system of the South Fork Palouse River Basin. Isotope analysis (δO18 and δH2) of snowmelt and groundwater is being used to identify areas of fast and slow groundwater recharge (differences in hydraulic conductivity) along the eastern margin of the basin where recharge can enter the aquifer system through a sedimentary unit at the mountain-front interface. Identification of the variation of hydraulic conductivity and recharge pathways will assist in quantifying groundwater recharge by complementing a second project that is installing seismic stations along the mountain-front interface for monitoring groundwater flux. A velocity analysis of low frequency perturbations in the ambient seismic field at each station will allow us to identify changes in sedimentary unit water levels from which we can calculate a flux of groundwater passing through the recharge zone.