Evaluating Houston area neotectonics using GIS and remote sensing techniques

Over 300 active faults intersect the Earth's surface in the Houston Metropolitan area. These surface faults have caused damage to roads, pipelines and buildings. Most of the faults form part of a regional down to the basin fault system along the northern coast of the Gulf of Mexico. In this study four kinds of information were used to improve characterization of the fault system: (i)lidar data, (ii)Ground Penetrating Radar (GPR), (iii)shallow seismic data, and (iv)GPS data.; i. Lidar data acquired in 2001 were used to remap the active faults of the area. A grid refinement algorithm for processing the raw lidar data to generate a 1.5 meter resolution DEM was developed. Spatial resolution of the scarps on the refined grids was improved and in some cases revealed features that were not observed on the unrefined DEM. Scarp heights were computed using the 2001 and a 1996 DEM. Hill-shading proved the best method for selecting faults for examination in the field.; ii. Shallow seismic data indicated possibly disturbed ground in the vicinity of the faults.; iii. GPR data also indicated possibly disturbed ground near faults.; iv. GPS data for the period from 1995 to 2005 showed ongoing subsidence in northwestern Houston and possible horizontal displacement towards the Gulf of Mexico.