A Dangerous Glacier Grows Inside Mount St. Helens' Crater

- Mount Saint Helens is no secret for those who like to climb and walk along its wide snowy slopes. Especially on the south side of the

mount

ain, it's easy to forget what this

mount

ain is capable of, unless you take a trip to the rim to remember it. This is as close as most people will get to the

dangerous

side of Mount St. Helens. A hostile and threatening

crater

that is out of reach of everyone. Well, almost everyone. After giving up our lives on liability forms, we were allowed to join the few scientists allowed to enter the

crater

.

But we were warned. - You are going to enter an active volcano. Steam explosions could occur. You're dealing with poison gas. You're dealing with the weather, I mean, you're entering a hostile environment. You are just a visitor and I hope you are welcome. - Our helicopter hovered briefly, over the thirty meter high Loowit Falls, before landing on the northern edge of the crater. - We are right about the explosion. In reality, we are right on the edge of the creator, right here, and if it were to go off, as it did in 1980, we wouldn't be alive to talk about it. - Our only means of transportation to get out of here flew away, leaving us alone for the day, and in a matter of minutes we got a taste of what is considered normal in this place. - This is one of the reasons it's closed to the public, some of these falling rocks are actually as big as a Volkswagen.

And a helmet would be of no use to him. - Charlie Anderson led the way, heading deeper into the crater. He is an independent geologist and volcanologist. He knows the dangers better than anyone, but he's still excited to come here. - In fact, this is my one hundred and fortieth trip, since 1980, and this year is a bit disappointing, because I have only been here twice. I usually come here ten or twelve times a year. - The other researchers are here to help document the changes taking place in this exotic and otherworldly landscape. Traveling here is extremely difficult.

There are no trails in the crater and progress is slow. Further ahead is the 300 meter high volcanic dome, which has been growing violently and unpredictably since the 1980 eruption. - The last dome building event was in October 1986. We had unannounced steam eruptions between 1989 and 1991, and I was in the crater when one of them exploded, and all I did was go behind a rock. and just pray, and the thing threw ashes and stuff, about sixteen or seventeen thousand feet above the dome. And we were wondering if we would ever get out of that, you know. - Today everything is calmer.

Everyone is cautiously cautious, but eager to discover what lies ahead. - It is an adventure. I can't help but be a geologist, I mean, I have a volcano in my backyard, an active volcano. - Chris Barrens has been with Charlie on more than 40 research trips to the crater. - There is a cross section of about 3,000 years of history, so reading the historical part of past eruptions and present eruptions, for me as a geologist, is extremely exciting. - The question every geologist asks is when will this mountain erupt again? Predicting that is the most complicated part of volcano science.

But there are other changes going on here, worth understanding and possibly worth worrying about. One of the most recent dangers is a

glacier

that straddles both sides of the dome. That's much bigger than it seems at first glance. - These lines here are cracks. Cracks in a

glacier

show glacial movement and it is actually moving down the mountain. From September 2002 to July 2003, the glacier moved down the mountain 60 feet. Which is incredible. In July 2003 there was about 80 feet more snow than last year at that time. -Charlie was one of the first to document the formation of the glacier and his research indicates that it is growing unusually fast. - I don't think anyone in the world has seen a glacier grow almost from the first snowflake.

This is the fastest growing new glacier in the continental United States. While most glaciers in the mountains are beginning to retreat due to global warming, global warming continues to advance. One of the many reasons this glacier advances and builds up is that it is on the north side of the mountain, which has little sunlight, so shadows prevent the snow from melting. - Wow. - A constant flow of dirt and rocks also ends up scattered on the ice. This layer of debris forms an insulating blanket that prevents the ice from melting and allows the glacier to grow larger and larger.

Glaciers, of course, are not uncommon in the Cascades. But the rapid pace of growth of this glacier sets it apart from others in the northwest. Just 50 miles away is Mount Rainier, a more typical Cascade peak, with several dozen named glaciers straddling the mountain's flanks. Rainier's glaciers are well-known, extensive, and visible from virtually anywhere. But Rainier is a relatively dormant volcano and its glaciers are shrinking. By contrast, the unnamed Saint Helens Glacier is growing rapidly and sits atop a restless, earthquake-prone volcanic crater. - One of the dangers would be that the volcano becomes active again. There is a pretty good source within the crater itself, from a lahar, you know, a flow of mud that emanates from the crater, if there is a significant eruption. - It's happened before.

During the 1980 eruption, glaciers at the top of the mountain dissolved, uniting rocks and other volcanic debris, to form a huge lahar, which ran down the Toutle River valley. This is not a scene residents want to repeat. At the USGS National Volcanic Laboratory in Vancouver, Washington, seismographs act as an early warning system, collecting real-time information about earthquakes and tremors from sensors placed on the mountain. - We are always monitoring Mount St. Helens, because it is the volcano that most frequently erupts in the Cascades. - Hydrologist Steve Schilling says there is reason to pay attention to what is happening in the crater. - Because it erupted in 1980, it did not eliminate all dangers.

So I can show you, as a comparison here between 1980 and 2000, and you can see as I turn it on and off, the dome

grows

and the increase inside the crater, like a horseshoe shape around the dome, of the snow. , and ice and rocks that are accumulating, so it's a pretty quick period of time for this glacier to develop. Over time, what this will do is fill up, and who knows how many years from now, we will eventually have a mountain as it looked before the 1980 eruption. And one day it will erupt again. - Studying the glacier helps scientists calculate how much ice, snow and rocks are accumulating.

And whether something other than an eruption, like a large earthquake, could cause a lahar, is one of the things geologists want to find out. But the glacier is now large enough that a lahar, if it occurs, would likely cause considerable damage. - This used to be almost flat, or let's say with a slope of ten degrees, if you remove all that mass, surrounding the entire dome, that is the amount that has accumulated since 1986. The danger of the lahar would be tremendous, because all the glaciers which were destroyed in 1980, half of that disaster is back in the crater, right now.

It would take five million dump trucks just to remove all that mass of snow. - The Toutle River valley still bears the wounds of a series of lahars that occurred in the 1980s. The danger today worsens, because the mountain gorge has been left completely open and only an aging sediment dam, miles downstream, remains. gets in the way of the next debris flow. This dam is filling up and becoming less and less effective over time. Things have been quiet for many years, but the visible damage from past lahars serves as a reminder that the mountain upstream should not be ignored.

Back at the crater, Charlie continues to document the growth of the glacier. But recent trips have become explorations of the hidden and previously unknown world of ice caves. - There are actually 26 entrances up here, and there is a mile and three quarters of cave. The caves continue to expand and sometimes collapse in different places as the glacier continues to advance. - The caves hide many hot spots in the crater, which constantly move, collapse and change shape. So, Charlie keeps his trips to the cave brief. - In the caves it is very

dangerous

, because at certain times of the year, like in 1998 for example, we had 445 earthquakes in the month of August.

Basically we are studying to see how they form, if it is geothermal activity, and there is a lot of geothermal activity for the fumaroles that are starting this cave. - The caves are fogged with steam and underground vents spew hot and sometimes poisonous gases. Melting glacial ice joins these hidden fumaroles and earth vents beneath the dome, only to emerge as boiling streams cascading down the mountain. These thermal characteristics provide clues about what the mountain is doing, how active it is, how hot it is, and what kind of changes occur from year to year. - This is a geothermal spring or hot spring.

And here's a good example of the algae growing on it. The darker brown

grows

at a higher temperature and then you get the green, which grows at a lower temperature. The water in the fountain is probably about 170 degrees Fahrenheit. - Scientists will continue to monitor the mountain for increases in temperature, as well as any rise and shaking activity that could trigger a lahar. However, despite the abundance of strange geological activity in the crater, research suggests that the mountain is, in fact, colder than it was twenty years ago and is slowly calming down. People like Charlie are just beginning to put all this information together.

Still, there are reminders everywhere that this is a new land and a place where change, even violent change, is a constant. (crashing rock) By late afternoon, a mist had filled the air, caused by a near-constant cascade of rock falls and avalanches. Chris and Charlie agreed it was time to go. - It is a risk, it is a calculated risk, and that is part of the investigation. I mean, you know, if no one came into this kind of environment, no one would really know what was going on. It is a necessary thing to do. - As we took off and looked at the crater from a safer distance, we tried to pretend once again that Mount Saint Helens is the peaceful place many have come to think it is.

It's probably wiser to accept the fact that it's not.