Assessing Sinkhole Potential at Wink and Daisetta Using Gravimetry and Radar Interferometry

Abstract

Large sinkholes (50 to 200 m in diameter) formed over Permian bedded salt near Wink in western Texas in June 1980 and May 2002 and on the flank of a salt dome at Daisetta, Texas in May 2008. Residents, government officials, and industry representatives would like to better understand the potential for sinkhole formation and growth. We are applying several geophysical methods to better understand sinkhole precursors and assess the potential for future sinkhole development. At Wink, limited data on vertical ground movement from standard surveying has been greatly extended by satellite-based radar interferometry, which we are using to delineate areas having recent movement and determine rates of movement. Results from interferometry are guiding acquisition of high-resolution gravity data, which has identified shallow-source mass deficits that indicate potential for continued subsidence or sinkhole formation. At Daisetta, we are using interferometry to determine whether vertical movement preceded sinkhole collapse and gravimetry to identify areas where shallow mass deficits exist across the salt dome. These initial data are helping to design a more comprehensive subsurface investigation and develop a monitoring program based on radar interferometry and geodetic GPS measurements.