UC Riverside scientists can’t tell us when a major earthquake will hit. But they’ve developed a new technique to predict where.
In a paper published this summer in Geophysical Research Letters, UCR geophysicists Gareth Funning and Axel Periollat described how their method to identify where stress has been building along major fault lines correctly predicted the exact part of the Kamchatka Peninsula in eastern Russia where an 8.8 magnitude earthquake occurred in 2025.
“We had an idea where the strain was accumulating based on a relatively limited data set,” Periollat is quoted as saying in a UC Riverside press release. “Seeing it work so well confirmed that this approach has real potential.”
Their approach looks at the stresses that build up in subduction zones, where tectonic plates slide under one another. The earthquakes that occur on subduction zones are associated with the largest earthquakes, including magnitude 8.5 and greater. (In contrast, the San Andreas Fault, which runs from Eureka to the Salton Sea, straight through San Bernardino, is a slip-strike fault, where tectonic plates slide against one another, with almost no vertical motion.)
“Large earthquakes occur where tectonic plates are locked together by friction and accumulate strain over time,” the pairs’ paper reads in part. “Our results identify a major locked region that had accumulated enough strain since the last great earthquake in 1952 to explain the size of the 2025 event. Within this region, smaller, persistent locked areas appear to control where rupture begins.”
The UCR researchers used GPS data to measure subtle ground movement. That data, in turn, became the basis for a new algorithm to identify parts of faults that are locked in place and storing pent-up energy. Eventually, the pressure gets to be too much, and the plates quickly move, triggering a major earthquake.
“For years beforehand the fault is quietly accumulating strain,” Funning is quoted as saying. “This strain can be measured.”
The new algorithm can’t predict the timing of an earthquake or how big of a tsunami it might trigger.
Funning and Periollat have now turned their tool to examine major subduction zones in Japan, Mexico, New Zealand and the Pacific Northwest, along with faults in California.
“In the Bay Area, the Hayward Fault has both creeping and locked sections, much like subduction zones,” Funning is quoted as saying. “We’re investigating whether we can identify the parts most likely to generate future earthquakes.”
And using the algorithm to look at earthquake risk around the world won’t happen until more GPS data is available. Little data is currently available about fault lines beneath the ocean, for instance.