Mount St. Helens May Erupt for Decades, Scientists Suggest

Mount St. Helens may continue its current slow eruption for decades, eventually rebuilding the dome that was blasted away when the volcano erupted in 1980, according to a geologist.

But the volcano, located in Washington State, could also stop erupting today (see Washington State map).

Daniel Dzurisin with the Cascades Volcano Observatory in Vancouver, Washington, is one of many scientists trying to understand when Mount St. Helens's most recent eruption, which began in October 2004, will end.

Several lines of evidence, he said, suggest the volcano's magma chamber a few miles below the surface is consistently resupplied with magma from an even greater depth.

If so, Mount St. Helens could keep erupting for decades or even centuries, in a so-called open system.

However, if the system is closed, the volcano's magma chamber will eventually be depleted, and the eruption will end.