This project aims at providing a near-surface hydro geologic mapping standard for better environmental management during resource development, in particular of shale-gas reservoirs.
The near-surface region—roughly, the first 500 meters below ground level—is highly variable in its physical properties, yet it is generally the most poorly characterized part of the earth involved in resource development. Satellite data and ground mapping usually provide excellent maps of surface features, while geophysical exploration technologies, such as seismic methods and well logs, provide details of deep-seated reservoirs, which generally lie at depths of 2 kilometers or more. But the region just below the ground surface is often not well characterized, even though this region supports much of the infrastructure of communities, including groundwater resources. New airborne geophysical sensors developed in the last decade have the potential of filling this information gap by mapping the near-surface hydro geologic environment in a way that can inform scientifically sound decisions about groundwater management and protection. The new technologies include broadband electromagnetic systems, high-precision gravity and magnetic gradiometers, and radiometric sensors flown at heights ranging from 30 to 200 meters above ground surface on fixed-wing aircraft or helicopters. The seed funding provided by YCEI will enable a feasibility study using geophysical data to build a hydro geologic model for a small area, roughly 5 km by 5 km, over the Marcellus shale in northwestern Pennsylvania. We hope to leverage this work into a full-scale pilot project, funded by a consortium of stakeholders, that will map near-surface above the Marcellus shale over its entire range. The project will be a collaboration of Geology & Geophysics Department, Yale Center for Earth Observation, School of Forestry & Environmental Studies, and Yale Climate & Energy Institute.