HR: 1340h
AN: H43F-0554    [Abstracts]
TI: Evaluation of Geophysical and Thermal Methods for Detecting Submarine Groundwater Discharge (SGD) in the Suwannee River Estuary
AU: * Weiss, M
EM: mwise00@hotmail.com
AF: Department of Geology, University of South Florida, 4202 E. Fowler Ave, SCA 528, Tampa, FL 33620
AU: Kruse, S
EM: skruse@chuma1.cas.usf.edu
AF: Department of Geology, University of South Florida, 4202 E. Fowler Ave, SCA 528, Tampa, FL 33620
AU: Burnett, W C
EM: wburnett@mailer.fsu.edu
AF: Department of Oceanography, Florida State University, Tallahassee, FL 32306-4320
AU: Chanton, J
EM: jchanton@mailer.fsu.edu
AF: Department of Oceanography, Florida State University, Tallahassee, FL 32306-4320
AU: Greenwood, W
EM: jgreenwood@usgs.gov
AF: USGS Center for Coastal and Watershed Studies, 600 Fourth Street South, St. Petersburg, FL 33701
AU: Murray, M
EM: mmurray@ocean.fsu.edu
AF: Department of Oceanography, Florida State University, Tallahassee, FL 32306-4320
AU: Peterson, R
EM: peterson@ocean.fsu.edu
AF: Department of Oceanography, Florida State University, Tallahassee, FL 32306-4320
AU: Swarzenski, P
EM: pswarzen@usgs.gov
AF: USGS Center for Coastal and Watershed Studies, 600 Fourth Street South, St. Petersburg, FL 33701
AB: In an effort to evaluate geophysical and thermal methods for detecting submarine groundwater discharge (SGD) on the Florida Gulf coast, a suite of water-borne surveys were run in conjunction with aerial thermal imagery over the lower Suwannee estuary in March 2005. Marine resistivity streaming data were collected alongside continuous radon and methane sampling from surface waters. Resistivity measurements were collected with dipole-dipole geometries. Readings were inverted for terrain resistivity assuming two-dimensional structure and constraining uppermost layers to conform to measured water depths and surface water conductivities. Thermal images were collected at the end of winter and at night to maximize temperatures between warmer discharging groundwater and colder surface waters. For the preliminary data analysis presented here, we assume high radon and methane concentrations coincide with zones of high SGD, and look at relationships between radon and methane concentrations and terrain resistivity and thermal imagery intensity values. For a limited set of coincident thermal intensity and radon readings, thermal intensities are higher at sites with the highest radon readings. These preliminary results suggest that in this environment, thermal imagery may be effective for identifying the "hottest" spots for SGD, but not for zones of diffuse discharge. The thermal imagery shows high intensity features at the heads of tidal streams, but shallow water depths precluded boat-based resistivity and sampling at these sites. Shallow terrain resistivities generally show a positive correlation with methane concentrations, as would be expected over zones of discharging groundwater that is fresher than Gulf surface water.
DE: 1830 Groundwater/surface water interaction
DE: 1835 Hydrogeophysics
DE: 4235 Estuarine processes (0442)
DE: 4808 Chemical tracers
SC: Hydrology [H]
MN: Fall Meeting 2005