Fault Investigations

Due to the ever-increasing shortage of useable land in Southern California, development has moved closer to the active fault lines that cross the state. In general, a fault investigation is required to precisely locate and evaluate the faults. The purpose is to prevent the construction of urban developments across the trace of active faults. An active fault is defined as one in which has had surface displacement within the Holocene Epoch (roughly the last 11,000 years). The State requires detailed fault investigations be performed so that engineering geologists can mitigate the hazards associated with active faulting by identifying the locations of active faults and allowing for a setback from the zone of previous ground rupture. These fault investigations typically involve background research, aerial photograph review, and field geology. If active faulting is suspected, a fault trench investigation is typically performed. The purpose of the fault trench investigation would be to allow a qualified geologist to evaluate the native materials and determine if and where faults transect the subject site.