Impact and Identification of Gulf Coast Faults

Carl Norman
Houston, TX

Although significant seismic activity is not generated along the hundreds of known active faults along the Gulf Coast, thousands of engineered structures built across them have undergone significant damage. The ultimate fate of these structures is abandonment and destruction long before their normal lifetimes. Lending institutions and developers, seeking to reduce financial risk, have supported an ever increasing number of fault investigations along the Gulf Coast, which in turn has resulted in identification of many previously unknown faults and extensions to those already known.

Geomorphic expression of the faults is often very subtle and occasionally absent, thus necessitating multiple geological techniques to identify and map individual faults. Once a suspected fault is encountered, drilling and geophysical logging of boreholes may be required to confirm its existence and map it in detail. Recognition of faults in the shallow subsurface requires a high degree of skill due to complex stratigraphy and to small amounts of throw on the faults. These conditions have rendered existing geophysical methods virtually useless for detecting and mapping of the faults with confidence.