MULTIDISCIPLINARY INVESTIGATION OF SURFACE DEFORMATION ABOVE SALT DOMES IN HOUSTON, TEXAS

Surface deformation has been an ongoing problem in the Houston Metropolitan area because of the city’s location in a passive margin where faulting and subsidence are common. According to previous studies the causes of the surface deformation are typically attributed to anthropogenic activities, mainly the subsurface withdrawals of oil, gas, and groundwater. However, the majority of the studies done have not accounted for the vast amount of salt underneath the Houston area and its role in the surface deformation. The objective of this study was to identify areas of surface deformation in the greater Houston area and their possible relationship with subsurface salt movements. To accomplish this, I integrated three kinds of data: 1) GPS, 2) LiDAR (Airborne and TLS), and 3) Gravity. GPS data revealed subsidence and uplift in Harris County. DEMs generated from airborne LiDAR revealed changes between salt domes and their surrounding areas. TLS data collected over the Pierce Junction site, chosen for accessibility and depth, revealed vertical changes over the surface above the salt dome. Gravity data acquired over Pierce Junction salt dome also revealed changes in the subsurface. Groundwater withdrawal may be a large influence in the surface deformation of the Houston area, but salt-related surface deformation should be more closely studied to quantify its influence.