GPS INSTRUMENTATION ON THE LONG POINT FAULT, HOUSTON, TX

The Houston Metropolitan area, and more broadly the Gulf Coast in general, has numerous growth faults that result in damage to engineering structures on or near the Earth's surface. Many faults in the Houston Metropolitan area are creeping at rates of 0.5 to 3 cm per year. These faults involve soft sediments, and as a result very little seismic energy is accumulated to produce destructive earthquakes. However, creeping along these faults causes moderate to severe damage to hundreds of residential, commercial, and industrial structures and infrastructure in the Houston area, requiring constant repairs that burden private citizens, businesses, and government agencies. We have installed 3 continuously operating GPS stations, with more to come, along a small segment of the Long Point Fault, a well-known active surface fault that spans much of the northwest and west part of the Houston metropolitan area. Twenty permanent benchmarks will also be installed along the two sides of the active fault. A repeated survey will be conducted twice per year. The objective of this study is two-fold: (a) to measure current creeping of the Long Point Fault, and (b) to demonstrate the feasibility of using GPS to monitor active faulting in an urban environment.