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... Deep below the Earth's surface, magma is churning and flowing into the Axial Seamount, an underwater shield volcano about 300 miles off the coast of Oregon. As the volcano grows and tremors increase, geologists are increasingly certain it will erupt soon -- possibly as soon as this year, and scientists from around the world will be watching closely if it does.

While this might sound alarming, the risk to even the closest human populations is minimal. Undersea volcanic activity doesn't usually pose significant danger to land, although it can produce powerful tsunamis.

In fact, the Axial Seamount last erupted just 10 years ago, but you probably don't remember it because the impact to humanity was nil. However, this volcano's predictable nature has made it popular in the geophysics community.

This volcano is the highlight of a chain of underwater mountains known as the Juan de Fuca Ridge (center of above image). These peaks straddle the North American and Pacific tectonic plates. As the plates move apart, magma from deep below the crust surges to the surface to build up the mountain ridges. Some of it collects in the Axial Seamount magma chamber. Careful measurement of the Axial Seamount can give scientists a good estimate of when it will erupt, and the signs point to "soon." ...