HYPERSPECTRAL REMOTE SENSING OF BRINE SEEPAGE FOLLOWING CATASTROPHIC RELEASE OF BRINE AND METHANE FROM THE SUBSURFACE IN HUTCHINSON, KANSAS

A fast, more spatially comprehensive method for locating brine microseepage from the subsurface is necessary to detect buried abandoned brine wells that were responsible for catastrophic gas and brine release in Hutchinson, Kansas on January 17, 2001. To date, traditional methods for detecting microseepage and buried well casing have been used. These mehods are reliable, yet are financially and temporally costly, labor intensive, and have a limited spatial coverage. A remote sensing method is proposed herein to detect effects of brine on surface sediments at high resolution and wide spatial coverage. The areas selected for this study were intially submerged in brine, but have since dried leaving a mineralogic crust at the surface. The distinctive spectra of salt can be used to delineate those areas that have been affected by brine seepage, versus unaffected areas. Preliminary in situ hyperspectral data acquisition has been completed using an ASD FieldSpec FR Sprectroradiometer. Comparison of the spectral reflectance data of the mineralogic crust to the spectral signature of halite (USGS spectral library) shows agreement between the two data sets. X-ray diffraction techniques were used to confirm the mineralogic crust as halite (evaporated brine). Based on successful results from the in situ hyperspectral data collection, data acquisition using an aircraft-mounted hyperspectral sensor (HYMAP) will commence and be collected concurrently with seasonal in situ hyperspectral field data acquisition. Those surficial areas within the city of Hutchinson, KS that exhibit the spectral response of brine will be investigated further using electromagnetic methods to determine whether the brine seep is coincident with abandoned brine well casing.