Earthquake Fault Zone Study & Investigation

The Alquist-Priolo Act of 1972 requires that an earthquake fault study be conducted on the geology of areas where a fault is known to be active and suspected of being capable of rupturing at the surface. Our geologists are trained experts at identifying faults and can determine the date of a fault’s last rupturing. When they need to talk with a geologist, Los Angeles residents, and those of the greater Southern California region, contact AES.

A fault study involves digging trenches, usually at least 3-5 feet wide, several dozen feet deep, and up to hundreds of feet long. These trenches are shored with steel braces to prevent caving. As part of the soil test, Los Angeles geologists from AES search for, and document, anomalies in the soil and rock layers. These anomalies can include features like offsets, gaps in the soil column that have been subsequently filled in with debris, and zones of intense folding or crushing. Soil samples from offset layers are sent to special scientific laboratories for radiometric or isotope age-dating. We are ready to extend to you our expertise when you need to assess the shape and state of a landslide in Los Angeles.