Investigation of Scale-dependent Groundwater/Surface-water Exchange in Rivers by Gradient Self-Potential Logging: Numerical Model and Field Experiment Data, Quashnet River, Massachusetts, October 2017 (ver. 2.0, November 2020)

This data release contains waterborne self-potential (SP) logging data measured during 48 laboratory experiments and three field experiments that were performed to develop an efficient, accurate method for detecting (in the laboratory) and geolocating (in the field) focused vertical groundwater discharge (surface-water gains) and recharge (surface-water losses) in a river. The experimental procedures and results are described and interpreted in a companion journal article titled "Remote detection of focused groundwater/surface-water exchange in rivers using waterborne self-potential logging: Laboratory and field experiments," and are similar to waterborne SP logging data measured, modeled, and interpreted by Ikard et al. (2017, 2018). The laboratory experiments were performed at the U.S. Geological Survey Texas Water Science Center, Austin, Texas in August - September, 2019. Controlled falling-head hydraulic experiments were performed to observe the polarities, transient rates-of-change, and peak amplitudes of streaming-potential voltages attributed to quasi-steady state vertical fluxes of groundwater through submerged coarse-grained and fine-grained sand aquifers of about 0.3 m in diameter. The laboratory experiments were substantiated with two three-dimensional finite-element numerical models representing the streaming-potential fields generated during surface-water gain and surface-water loss experiments. The field experiments were performed in the Quashnet River, Cape Cod, Massachusetts on October 11, 2017, along a 1.5 kilometer reach of the river where focused, meter-scale submerged groundwater discharges occur at discrete locations within otherwise more diffuse groundwater upwelling conditions into the river (Briggs et al., 2016a,b; Rosenberry et al., 2016).

1. Briggs, M.A., Buckley, S.F., Bagtzoglou, A.C., Werkerma, D.D. and Lane, J.W., 2016a, Actively heated high-resolution fiber-optic-distributed-temperature sensing to quantify streambed flow dynamics in zones of strong groundwater upwelling: Water Resources Research 52, 5179 - 5194.

2. Briggs, M.A., Hare, D.K., Boutt, D.F., Davenport, G. and Lane, J.W., 2016b, Thermal infrared video details multiscale groundwater discharge to surface water through macropores and peat pipes: Hydrological Processes 30, p. 2510 - 2511.

3. Ikard, S.J., Teeple, A.P., Payne, J.D., Stanton, G.P. and Banta, J.R., 2017, 14.86 km profiles of the electric and self-potential fields measured in the lower Guadalupe River Channel, Texas Interior Gulf Coastal Plain, September 2016: U.S. Geological Survey data release, https://doi.org/10.5066/F7CJ8CDH.

4. Ikard, S.J., Teeple, A.P., Payne, J.D., Stanton, G.P. and Banta, J.R., 2018, New insights on scale-dependent surface and groundwater exchange from a floating self-potential dipole: Journal of Environmental and Engineering Geophysics 23(2), 261-287.

5. Rosenberry, D.O., Briggs, M.A., Delin, G. and Hare, D.K. 2016a, Combined use of thermal methods and seepage meters to efficiently locate, quantify, and monitor focused groundwater discharge to a sand-bed stream: Water Resources Research 52, 4486-4503.