Houstonians may not feel it, but the ground beneath them is moving, and that could mean trouble for buildings and roads located on one of the hundreds of faults traversing the region's surface. Although geologists have long known of the existence of faults in Southeast Texas, only recently have University of Houston researchers produced a comprehensive map pinpointing the locations of the faults. Using advanced radar-like laser technology, Shuhab Khan, professor of geology, and Richard Engelkemeir, a geology Ph.D. student who has now graduated and begun his career, identified about 300 faults in Harris County. This information, the most accurate and comprehensive of its kind, could prove vitally useful to the region's builders and city planners at they create construction plans.
The shifting fault lines in Houston are not the kind that produce earthquakes. These faults can move up to one inch a year. That may not seem like much, but such movement over several years can cause serious damage to buildings and streets that straddle a fault line. Structures on the lower, subsiding side of the fault line may be more susceptible to flooding. Khan and Engelkemeir began by looking at data compiled during a 2001 study funded by the Federal Emergency Management Administration and the Harris County Flood Control District. The data was from an aircraft flying overhead, using laser beams to measure the topography of the ground. Khan and Engelkemeir pored over the data, refining the grids to identify more than 300 faults. Now Khan and Cecilia Ramirez, a student pursuing a Master's Degree in Geophysics, are expanding their research into Fort Bend County with information provided by the Fort Bend Flood Control District. With that and a new set of data collected in a 2008, Khan and his team plan to study to compare the changes in the Harris County fault lines over the past seven years. “This will help us understand what's driving the faults and help us be better prepared to deal with them” says Khan. The project will also help geologists have a better understanding of regional tectonics.
The Geosciences team have visited some of the faults and saw cracks in street pavements, foundation problems, and at one home there was one meter of displacement between the garage and the house. At another site a building had been so damaged by ground shifts it was condemned. To learn more about this fascinating research and other progressive geology projects, visit Khan's research project page.