Bursts of aftershocks, long-term precursors of strong earthquakes

Abstract

Earthquakes that are followed within a short time by abnormally large numbers of aftershocks are hypothesised to be long-term precursors of stronger earthquakes. In a test of the hypothesis, 18 out of 23 strong earthquakes, in five regions worldwide, were predicted retrospectively. In comparison with a random model the precursory pattern occurs at a satisfactorily high confidence level. © 1980 Nature Publishing Group.