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."