Earthquakes may strike without warning, but the ground beneath us is rarely completely still. Current systems can measure these tiny movements with remarkable precision, but until now, they have been used mainly to understand how faults behave rather than to predict where an earthquake might strike. Now, a new approach is challenging that limitation.
A team of researchers from the University of California-Riverside has developed a method to help identify where the biggest earthquakes are likely to occur. Using a GPS-based algorithm to measure subtle ground movements, the researchers can determine where a rupture might take place.
The findings, recently published in the Geophysical Research Letters, could potentially improve disaster response efforts in some of the most vulnerable regions.
Preparing ahead
Earthquakes happen when rocks in Earth’s crust suddenly move or slip along fault lines, releasing stored energy as seismic waves. As those waves move through the ground, it causes the shaking felt during an earthquake.
To help predict the location of a forthcoming earthquake, the researchers behind the new study say they can determine where stress has been building up beneath Earth’s surface. Earth’s tectonic plates move very slowly but can sometimes get stuck due to friction. As the plates attempt to move, that builds up stress in Earth’s crust.
Those tectonic fault lines quietly accumulate strain over years. The new method, according to the researchers, can measure that strain.
To do that, the team looks toward subduction zones, where one tectonic plate slides beneath another. The subduction zones tend to generate Earth’s most powerful earthquakes that exceed 8.5 magnitude and can sometimes cause tsunamis.
Using GPS measurements, the researchers say they can identify portions of faults that are locked and storing energy. These locked regions, known as asperities, act like patches of friction that resist motion until enough stress builds to trigger an earthquake.
What lies beneath
Using the new method, the researchers were able to identify one specific locked region beneath Russia’s Kamchatka Peninsula, where an 8.8 magnitude megathrust quake struck in July 2025. The event triggered a tsunami warning for the western United States.
Although the measurements could not identify when the earthquake will strike, it honed in on the exact location of the rupture where the model showed an area of accumulated strain. “We had an idea where the strain was accumulating based on a relatively limited data set,” Axel Periollat, a geophysicist at the University of California-Riverside and lead author of the study, said in a statement. “Seeing it work so well confirmed that this approach has real potential.”
The team is now looking at other major subduction zones in Japan, Mexico, New Zealand, and the Pacific Northwest. “We can identify where large earthquakes are likely to occur, even if we can’t predict exactly when,” Periollat said. “With better observations and continued monitoring, we can learn much more about Earth’s most dangerous faults.”
Still, the researchers stress that forecasting earthquakes should complement, rather than replace, public preparedness for the event. “Your peace of mind shouldn’t come from believing we can forecast the exact earthquake,” Gareth Funning, a geophysicist at UCR and a co-author of the study, said in a statement. “Especially where we live in Southern California, it’s not a matter of if, but when. There is no substitute for preparation.”
