Taking the stress out of earthquakes

The Swedish Defence Research Agency, FOI, has developed a method of stress analysis in earthquake research which could lead to earlier and more accurate earthquake predictions.

The analysis method makes it possible to estimate the complete stress tensor and monitor changes in the magnitude of stress and the instability of faults. This makes it more accurate, facilitating efforts to provide warnings.

The technique also uses micro-tremor data, for quakes with a magnitude of between -1 and 5, which offer the greatest possible amount of information for the analysis.

Tests with Icelandic micro-tremors from 1990 to 2005 yielded excellent results, with the major earthquakes occurring precisely when they were predicted by the stress analysis. This experiment indicated that the sites of coming earthquakes can be determined years before they occur.

‘What is crucial to whether the analysis is reliable is to what extent the small quakes are analysed,’ said the scientist behind the method, Ragnar Slunga.