Seeing the Fault Lines: How New Technology Is Reshaping Utah’s Earthquake Maps
Seeing the Fault Lines: How New Technology Is Reshaping Utah’s Earthquake Maps
Publish Date: 2026-05-20 11:36:00
Source Domain: www.geoweeknews.com
The ground beneath central Utah tells a story of seismic history, one that scientists are only now learning to read clearly.
If you were to set foot in the Sevier Valley in Utah, the landscape might look deceptively still. However, beneath that quiet is a loud history, and the geologists at the Utah Geological Survey now have a way to read it.
Using lidar, UGS Project Geologist Adam I. Hiscock and his colleagues have spent years painstakingly remapping the active faults that crisscross central Utah. What they’ve found is both illuminating and sobering: the region’s earthquake hazard is more complex and more present than older maps ever showed.
The Tool That Changed Everything
Before lidar, fault mapping was hard, imprecise work. Geologists relied on aerial photographs, paper topographic maps, and long days of fieldwork to trace the subtle scars that earthquakes can leave on the landscape. These scars, known as fault scarps, are step-like features formed when the earth ruptures along a fault line during a major earthquake. Small ones, or those hidden beneath thick vegetation, were easy to miss until lidar changed the equation entirely.
By sending out millions of laser pulses from aircraft and measuring how long each one takes to bounce back, lidar can digitally strip away trees and brush to reveal the bare earth surface beneath. The result is a strikingly detailed three-dimensional model of the ground, one that exposes fault scarps that have been quietly sitting there for thousands of years, invisible to previous methods.
“Lidar is an incredibly powerful tool,” says Hiscock. “Being able to generate a ‘bare earth’ 3D model of the ground surface and see through vegetation allows us to map very small and eroded fault scarps that were previously impossible to detect using older methods.”
The new mapping, which covers parts of six counties: Garfield, Juab, Millard, Piute, Sanpete, and Sevier, reveals more detail and complexity than anything produced before. Faults that…
