Volcanoes: Star of the Earth Show

Crowds Gather at Mount St. Helens; Waiting For a Wreck to Occur?

Some had camped out, sitting in lawn chairs, drinking coffee, talking to friends; some with binoculars around their necks grilled hamburgers and franks, while others sold t-shirts and took pictures of friends and families.

If you didn't know better, you would have thought it was a tailgate party — but these people weren't in the parking lot at Kyle Field or Boone Pickens Stadium. They were preparing for the geological equivalent of another Star Wars sequel: the eruption of Mount St. Helens.

But the movie's release has been delayed.

One of nature's great ironies is that volcanoes — unlike its black sheep brethren, the tornado and hurricane — attract rather than repel people to its pending wrath. In fact, while people desperately try to flee a tropical storm, they'll make hotel reservations near an erupting volcano.

Further, after the show is over, nobody comes to see the ravages of Hurricane Ivan or Jeanne; by contrast, 1.5 million tourists have visited Mount St. Helens since May 18, 1980. As one resident who had lived through that blast and was waiting for this one said, "(Last time) the mountain came to us. This time, we came to the mountain."

Image Caption

Scientists, laymen and tourists have a lot in common — compelling curiosity — when volcanoes threaten. Mount St. Helens, as seen on Oct. 3.
Photo courtesy of U.S. Geological Survey

Please log in to read the full article

Some had camped out, sitting in lawn chairs, drinking coffee, talking to friends; some with binoculars around their necks grilled hamburgers and franks, while others sold t-shirts and took pictures of friends and families.

If you didn't know better, you would have thought it was a tailgate party — but these people weren't in the parking lot at Kyle Field or Boone Pickens Stadium. They were preparing for the geological equivalent of another Star Wars sequel: the eruption of Mount St. Helens.

But the movie's release has been delayed.

One of nature's great ironies is that volcanoes — unlike its black sheep brethren, the tornado and hurricane — attract rather than repel people to its pending wrath. In fact, while people desperately try to flee a tropical storm, they'll make hotel reservations near an erupting volcano.

Further, after the show is over, nobody comes to see the ravages of Hurricane Ivan or Jeanne; by contrast, 1.5 million tourists have visited Mount St. Helens since May 18, 1980. As one resident who had lived through that blast and was waiting for this one said, "(Last time) the mountain came to us. This time, we came to the mountain."

The thought was that by the time this article came out, Mount St. Helens would have already erupted and etched a new memory into the surrounding landscape. There was the fear of people being trapped, planes being grounded due to ash and another made-for-television movie being filmed with another mythical figure with a name like Harry Truman.

None of that has happened; in fact, the most notable effect so far of last month's activity is that October 27's lunar eclipse appeared brighter and more copper because of all the steam the mountain let off.

Lava Growth Continues

Presently, according to the U.S. Geological Survey, growth of new lava inside the crater of Mount St. Helens continues, and as long as it does, major changes in activity, including eruptions, can occur with little warning.

While seismic levels remain at a low level compared to the levels of late September-early October, the activity at deadline was still producing a slow rise of magma. However, the relatively low rates suggest that the lava reaching the surface is gas poor, thereby reducing the probability of highly explosive eruptions in the near term.

Until waves of molten lava start racing down the mountain, geologists will have a chance to smoke 'em if they got 'em, review their notes and put the past few months in perspective.

According to the USGS, when Mount St. Helens erupted in May 1980:

  • It lost 1,300 feet in elevation within 20 seconds, destroying the Toutle River valley (burying the North Fork in debris as much as 600 feet).
  • Twenty-four megatons of thermal energy were released and four billion board-feet of timber were blown down (or enough for 300,000 homes).
  • The landslide created was the largest on earth in history, triggering powerful explosions of 300 miles per hour.
  • Over the course of the day, prevailing winds blew 520 million tons of ash eastward across the United States and caused complete darkness in Spokane, Wash., 250 miles from the volcano.

Of the four lakes in the blast zone (Spirit, St. Helens, Fawn and Venus), Spirit was the most affected. While other lakes received varying amount of pyroclastic material, Spirit's surface area increased from 1,300 acres to a little over 2,200 acres. Considering as well the iron, calcium, sodium, potassium and magnesium increase and the alkalinity of the water, the USGS concluded that Spirit Lake "was affected to the extent that it must now be considered a completely different lake. It has increased in area, decreased in depth and risen 240 feet in altitude as a result of the eruption. The surface of the lake is covered with logs, and the outlet to the North Fork Toutle River has been blocked."

That Was Then, This is …

Scientists, who euphemistically refer to what went on at the mountain last month as "throat clearing," say that even in the event of a larger eruption there is hardly any chance of a repeat of the mountain's lethal 1980 explosion or of Hawaiian-style lava flows. The mountain is in the middle of a large national forest and the nearest community is 30 miles away, so any activity will occur over rural areas.

(Of course, Mount St. Helens was in a rural area in 1980, as well).

For the time being, experts believe that populated areas will get little ash if the current light west-northwest wind holds.

The biggest fear is that an eruption could melt the volcano's 600-foot-deep glacier and trigger debris flows to the barren pumice plain at the foot of the mountains. Long-term effects of a significant eruption include increased hazards of catastrophic flooding due to the rearrangement of local terrain by volcanic debris that will block parts of the area's natural drainage system.

For now, though, there is no panic and the chief concern is that a significant ash plume laden with pulverized rock and silica could damage aircraft engines and the surfaces of cars and homes.

Predicting the force, devastation, or even temperament of a volcano is not something intelligent scientists discuss for very long, though. Even though Mount St. Helens appears for the moment to be napping, as Peter Frenzen with the U.S. Forest Service recently said (and we may already know this by now), "the volcano reserves the right to change its mind."

zezusacrzebvrecaswwssyfvcfsudzebutc

You may also be interested in ...