Scientists at the University of California, Riverside, have created a new method to identify areas where the largest earthquakes are most likely to occur. This tool doesn’t predict when an earthquake will happen, but it helps locate regions where stress is building along major fault lines, increasing the chance of a rupture. In a recent study published in Geophysical Research Letters, the team tested their model on the Kamchatka subduction zone in eastern Russia. Their model correctly identified the exact section of the fault where a major earthquake occurred later, demonstrating the potential of the method for improving disaster preparedness in high-risk areas. Subduction zones, where one tectonic plate slides beneath another, are responsible for the largest and most destructive earthquakes, often exceeding magnitude 8.5 and generating devastating tsunamis. The UCR researchers, led by geophysicists Gareth Funning and Axel Periollat, focus on how the Earth's surface deforms as tectonic plates lock together before breaking. Using GPS data, they developed an algorithm that detects locked regions of faults—areas known as asperities—where energy is stored until enough stress causes a rupture. These locked sections are key to understanding where major earthquakes are likely to occur. The study revealed that even in the same region, earthquakes can behave differently. For instance, two major quakes struck the Kamchatka Peninsula in 1952 and 2025. While both were large, the 2025 event caused a much smaller tsunami, suggesting that the shallower part of the fault moved less than it had in 1952. However, the researchers emphasize that their method does not predict earthquake timing or tsunami size. Instead, it helps identify areas with the highest seismic risk, which can improve long-term planning and preparedness. The team is now applying their approach to other major subduction zones, including Japan, Mexico, New Zealand, and the Pacific Northwest, each of which presents unique challenges. To expand the use of this method globally, scientists need more data, especially in areas where fault lines lie beneath the ocean. While GPS stations on land provide valuable information, offshore measurements are limited. Researchers in Japan are using acoustic instruments placed on the seafloor to monitor slow deformation over time, and similar efforts are being considered in other regions like Chile and the Pacific Northwest. A new satellite may also help fill in gaps in GPS coverage. Despite these advancements, the researchers stress that earthquake forecasting should support—not replace—public preparedness. As Funning noted, in places like Southern California, the focus should be on readiness, as earthquakes are inevitable, not if, but when.