Seattle — Follwing last week's eruption of Mt. St. Helens, the biggest question with both geologists and economists in the Pacific Northwest is how long the mountain will remain active.
The last time the volcano cut loose, in 1831, it erupted sporadically for about 25 years.
ACcording to US Geological Survey (USGS) experts, St. Helen's past holds both single and multiple eruptions.
Until last Tuesday, volcanologists had begun to think that the mountain was settling down for an indefinite period.
"A lot of people were becoming complacent, thinking it was about time to leave," acknowledges Tim Hait of the USGS.
Until then events had proceeded like a textbook example of the cycle of an explosive volcano.
First there was a period of passage clearing accompanied by seismic activity and smoking. Next came the big eruption. Then there was a series of successively smaller outbursts. A lava dome began forming in the crater. According to the textbook, the next step should have been a cessation of activity.
However, last Tuesday's eruption, which did very little direct damage, did not follow the textbook.
Now "nobody really knows what St. Helens is going to do," maintains Richard Cadle of the National Center for Atmospheric Research. He specializes in the atmospheric effects of volcanic eruptions and can cite numerous examples of volcanoes that have confounded the experts.
Thus the latest eruption has created uncertainties that extend beyond the domain of the volcanologists into the realm of the economist.
Last month, reporters for the Wall Street Journal concluded that the Volcano's activities have "cast a pall over the economic future of the Pacific Northwest."
While this assessment has been strongly criticized here, there is little doubt that Mt. St. Helens has had a number of adverse economic effects. On the other hand, it has had some beneficial aftereffects as well. And the net effects appear as unpredictable as the volcano's future activities.
The most obvious and easily measured economic consequence of the recent eruptions is the direct destruction which has occurred. The Federal Emergency Management Administration puts the costs at $767 million.
The most discussed indirect economic effect is that on tourism. Both Washington and Oregon have reported a 10 to 20 percent decline from a year ago. According to economic experts in the two states, however, it is impossible to determine how much of this decline is due to the nation's deteriorating economy, the abnormally rainy weather here this spring and early summer, or the volcano.
Offsetting those who cancel due to the widespread and erroneous perception that the entire region is blanketed in ash, are the tourists who have been attracted by the allure of seeing an active volcano. So far the volcano seekers appear much smaller in number than those who are avoiding the area, but their ranks seem to be swelling rapidly.
"The long-term effect on tourism could even be positive once the mountain quiets down, especially for Portland which would serve as a staging area," maintains Denny Miles, an assistant to Oregon Gov. Victor Atiyeh.
Still, it is unlikely that Oregon will continue to advertise itself as the place to come to ski on the slopes of a real volcano.
Another widely bruited form of economic impact is the effect on industries considering relocation in this area. Of particular concern have been semiconductor firms which need a particularly clean environment.
National Semiconductor Corporation, for instance, decided last month not to go ahead with a $70 million plant in Vancouver, Wash., just across the river from Portland. They blamed Mt. St. Helens for the decision. But state officials who have been following the situation believe this was more of an excuse than a primary reason for the decision.
Following this, a group of Seattle economists surveyed other semiconductor and computer manufacturers in the area and learned that the eruption neither caused them to consider moving existing plants nor would figure as a major factor in deciding to locate new plants in the area.
The effects of ash fall on agriculture also seem minimal. Despite the eruption Washington State is having bumper crops, reports Carl Hunt, an analyst with the Department of Commerce and Economic Development.
Crop destruction was quite localized and to a certain extent offset by the fertilizing characteristics of the ash.
The consequences of future eruptions on agriculture, should they occur, depend on the time of year and the amount of ash, Mr. Hunt points out. Although there was little ash in the last eruption, there is no guarantee this would hold true for a subsequent one, experts say.
As for the effect of repeated eruptions on downwind communities, such as Yakima, Mr. Hunt believes it is similar in many ways to heavy snowfall. Once cities develop the capabilities to cope with it, then it represents only a temporary impediment to travel.
The economist does see one possible adverse effect should Mt. St. Helens remain active: It could increase the cost of money in the area if Eastern investors remain wary.