On May 18, 1980, the once bucolic ice-cream cone shape that defined Mount St. Helens in Washington state disappeared in monstrous blast of ash, rock, gas, and heat.

It was one of the most powerful explosions ever witnessed by humans and the force of the blast leveled hundreds of square miles of forestland, devastated wildlife and killed over 50 people.

Almost three decades later, the effects of the eruption are readily apparent to the thousands of visitors to the observation points in the sprawling Mount St. Helens volcanic monument.

But time has also muted the effects to some degree. Trees are growing back in some areas, plants have poked up through the ash, animals move through the devastated plains once again.


And inside the volcano, which was once a soft dome of snow but is now a gaping, steaming menace with an unpredictable streak, an unexpected phenomenon is taking place: a glacier is growing.

In these days of global warming concerns and scientists showing alarming then-and-now images of glaciers disappearing from mountainsides, it may be the only growing glacier in America - or maybe the world.

Scientists closely monitoring the unlikely growth of the glacier say the north-south orientation of Mount St. Helens' huge crater plays an important role in growing the ice formation.

The eruption 28 years ago hollowed out the center of the mountain and thrust it almost directly north, leaving a towering crater wall to shield the crater's interior from the melting effects of the sun during most months of the year, especially the winter months.

Over the years since the huge eruption, the snowfall has condensed and compacted to form a horseshoe-shaped glacier inside the crater.

Researcher Joseph Walder with the U.S. Geological Survey says the shade from the crater wall is allowing the glacier to grow in height by about 15 feet per year.

But that's not the only thing driving the unlikely growth of the glacier, which shares the crater with a lava dome that is hot enough in most places to instantly boil water.

Recent spasms of dome-building activity in the crater have forced the two arms of the glacier to move towards the mouth of the crater, where they now almost touch.

Eventually, if they do connect, the frozen glacier will completely encircle the smoldering lava dome, forming a cold collar around the furnace in the middle of the mountain.

But Walder cautions that a glacier inside a volcano leads a tenuous existence. A surge in volcanic activity, especially an eruption, could melt away the glacier in the space of a day, sending a torrent of water down the Toutle River in a flood that would bring widespread destruction downstream.

The damage could echo the devastation wrought by the volcano 28 years ago when the rapid melting of snow and glaciers during the May 18 eruption sent muddy walls of churning water streaming from the volcano, taking out bridges, homes and trees as it rushed downhill.

So far, there is no known way to accurately predict when such volcanic activity is due to take place. Mount St. Helens' volatile nature could trigger the death of the glacier at any time.

Meanwhile, Walder will continue to work on making mesmerizing time-lapse movies of the ice-field's movements and studying the creeping glacier as it moves to encircle the steaming center of fire at the heart of the Mount St. Helens volcano.