Volcano experts watch and wait.

Mt. St. Helens is erupting and scientists as well as people living in Washington state are anxious to see what it does next.

The activity started in October when the volcano started forming a new lava dome or mound. If the eruption gets more intense, it could be powerful enough to send a huge burst of debris into a nearby river valley. The ash could fly high into the air above Mt. St. Helens, becoming a health hazard for people in that area and limiting visibility for airplanes.

But for now, the volcano activity is slower and less intense, according to Carolyn Driedger of the U.S. Geological Survey in Vancouver, Washington. Still, Mt. St. Helens could stay active for weeks or months and its activity level could suddenly change. In 1980, Mt. St. Helens erupted and 57 people died. Molten rock rising from the volcano caused part of the north slope to weaken and slide away. What's left now is shaped like a horseshoe.

To imagine what the current eruption looks like, Driedger says, think of the crater as a cup. Inside the cup, on the bottom, is where the eruption is happening. Thick lava is rising to the surface and forming a big dome or mound, like toothpaste coming out of a tube. The lava is quite stiff so it isn't flowing too far.

On the Web, you can see what the 8,364-foot-high volcano looks like on the Mt. St. ...