Rock defects below earth surface impact quakes

Sydney, April 24 (IANS) Defects in rocks lying below the earth's surface can modify the impact of seismic waves generated by earthquakes, says a study by the Australian National University.

"We found that defects, known as dislocations... will help us better interpret seismological models of the earth's internal structure," Ian Jackson, a professor from the Research School of Earth Sciences at the university, was quoted as saying in the journal Science.

"These defects have long been considered responsible for the motions of the earth's mantle, which have facilitated the movement of tectonic plates over millions of years," said Jackson.

The study's co-author, John Fitzgerald, also from the Research School of Earth Sciences, said these findings allowed for a better understanding of how the materials below the earth's surface transmitted seismic waves, such as those tied with earthquakes.