Scientists get a closer look at mechanism of Deep Bolivian Quake

While big earthquakes typically wreack havoc for humankind, the biggest deep earthquake ever recorded—the magnitude 8.3 event that occurred 637 km beneath the surface of Bolivia on June 9, 1994—has brought enlightenment—of sorts.

Instead of bringing death and destruction, the recent Bolivian quake, the largest quake of any type in recent decades, has given scientists one of the best probes yet of the Earth's interior. Within several minutes of the deep rupture, the quake benignly shook the ground from Argentina to Canada. But more important, the quake shook the Earth like a bell for months thereafter, giving scientists a raw data set of the planet's free oscillations—like none other.