Earthquake forecasting

摘要

Naturally-formed balancing boulders could be used to help scientists to forecast large earthquakes more precisely. Precariously balanced rocks (PBRs) are found throughout the world (characterised by a slender boulder on a pedestal boulder) and have survived earthquake shaking over thousands of years. They can, therefore, indicate the upper limit of earthquake shaking that has occurred since they were first formed - shaking that, were it strong enough, would have caused them to topple.