Switched-Field Surface NMR for Enhanced Detection and Resolution of Shallow Groundwater

C47-24c-271412This proposal addresses the challenge of non-invasively, economically, and accurately detect and imaging groundwater and hydrogeological properties in the top 30m of the subsurface. We will apply imaging methodologies at the core of medical MRI to efficiently map shallow groundwater and hydrogeologic properties at improved resolution. Conventional surface NMR has been proven as a powerful non-invasive technique for coarse groundwater imaging. The method is limited, however, by simplistic imaging protocols. To enhance sensitivity and spatial resolution, we will introduce “switched-field” NMR.This new paradigm combines gradient and prepolarization fields to allow localization of signals based on their frequency and phase response and will increase the signal-to-noise ratio for shallow water. In addition to improving resolution, these approaches will also accelerate measurement speed allowing the technology to be applied in a wider range of environments and markets. The Phase II2B tasks will engineer and commercialize a new ultra-lightweight, low-cost surface NMR instrument with greatly expanded measurement capabilities, for groundwater investigations up to 30m. This new product will incorporate the switched field detection and imaging methods developed and demonstrated in Phase II. Completion of this technology will deliver a powerful groundwater imaging product for commercial sale, rental, and/or services in the environmental, geotechnical, and subsurface research markets. This technology will be of value to companies, governments, and public agencies facing problems such as groundwater contamination, dewatering for geotechnical engineering, and permafrost mapping. The ability to image at high-resolution in with reduced survey times will improve the reliability of subsurface models, reduce site characterization costs, support informed decision making. In turn, this technology will improve project efficiency, reduce risk, and result in improved outcomes.