Thar She Blows!; June 2012; Scientific American Magazine; by Charles Q. Choi; 1 Page(s)

Earthquakes often precede explosive volcanic eruptions such as the devastating outburst from Mount St. Helens in 1980. But attempts to use tremors to predict the timing and force of such explosions have proved unsuccessful for decades. Now multidisciplinary teams of researchers have developed models that could help warn of disastrous eruptions hours to days before they happen.

A group of scientists at the University of Leeds in England investigated the mystery of why volcanic tremors come in clusters and why they can occur at multiple depths within volcanoes. The answer may lie in how magma behaves: much like Silly Putty, it shatters if pulled apart quickly. When magma rising within a volcano’s main conduit ruptures, the magma develops deep cracks. These cracks weaken the magma, helping it rupture at other points and flow more quickly, which causes still more shattering to occur.