Scientists had already made a detailed assessment of earthquake risks at Rood’s research site. That’s because along with balanced rocks, the location is home to the Diablo Canyon nuclear power plant, which for safety reasons had to be built to withstand quakes. Rood’s team compared this existing assessment with their new results. Their findings suggested that the biggest expected earthquake over the next 10,000 years would be about 27 percent weaker than previously projected. That’s great news for the nuclear plant and surrounding communities.
Their results also suggest that data from balanced rocks could reduce the uncertainty in local earthquake estimates by half. But scientists shouldn’t overhaul current risk assessments just yet. “These are models based on very detailed studies and data,” says Rood. No individual part seems wrong. Before making changes, says Rood, it’s important to find out why previous assessments varied so dramatically from her team’s findings.
Rood is planning a larger study of rocks from several sites across Southern California. Bringing together data from multiple locations may help unravel the key factors needed to make more accurate earthquake risk estimates. Rood looks forward to getting out into the field with balanced boulders again. And if you ever spot a cool balanced rock in nature, she says, you should resist the urge to give it a push: You might unwittingly erase tens of thousands of years’ worth of important data!