The unstable equilibrium rock, known as PBR in geological circles, is an ancient and delicate natural structure, which can provide scientists with interesting clues about earthquake disasters in this area. By understanding the upper limit of the rocking that these rocks have been subjected to in the past, researchers can get a picture of the future seismic risk in the area, and a cutting-edge new technology can greatly improve the accuracy of this modeling. < / P > < p > for decades, scientists have been turning to PBRs to assess seismicity and future seismic risk, and these long-standing rock formations are evidence of local seismic limits that have occurred for thousands of years. This information, together with other factors such as fault lines, provides a basis for earthquake disaster modeling that engineers rely on to determine the safe location of bridge dams. However, there are many loopholes in this method. One of the major problems is the lack of seismic data of large earthquakes rare from 10000 to 1 million years ago. A team at Imperial College London has come up with a way to fill these gaps by studying the ancient geological secrets of a PBR in California. < / P > < p > this involves using a technique called cosmic ray surface exposure age to count the number of rare beryllium atoms in rocks, which is the result of long-term exposure to cosmic rays. This allows the team to determine how long the PBRs have existed in their current arrangement, and use 3D modeling software to recreate the rocks and simulate how much ground shaking they need to fall. < / P > < p > a team at Imperial College London has found that PBRs, or unstable and balanced rocks, can last twice as long in the landscape as previously assumed. The new data are combined and compared with the existing models to improve the accuracy of the model. According to the team, this helped them eliminate a series of assumptions in modeling, ultimately reducing the uncertainty of earthquake disaster estimates by 49% and reducing the average size of rare earthquakes estimated to occur every 10000 years by 27%. We are on the verge of scientific breakthroughs in earthquake prediction, said Dr Dylan rood, co-author of the study. &Our rock clock technology has the potential to save huge costs of seismic engineering and can be used to test and update site-specific hazard estimates in earthquake prone areas – especially in coastal areas, where the source of the earthquake is an offshore fault, and its movement itself is more difficult to investigate. &Researchers are now turning their attention to improving risk estimates in Southern California, a densely populated area of the United States and particularly vulnerable to seismic activity. We are now studying PBR near major seismic faults such as the San Andreas fault near Los Angeles, said Anna rood, lead author of the study. &We are still working on how to determine which data – whether fault slip rates or the choice of ground motion equations – are distorting the results of the original hazard model. In this way, we can further improve scientists’ understanding of large earthquakes. "Global Tech