Wednesday, May 19, 2010

May 19, 1980

I got really backed up yesterday, spending most of the day reading and blogging about Mt. St. Helens to the exclusion of pretty much all else. Still, I feel like I've hardly scratched the surface; there's just so much to say about this fascinating eruption. Above, adapted from USGS Professional Paper 1250, is a schematic illustrating some of the points I discussed in yesterday's post.

A point I'd like to emphasize today though is how little was known or understood in the days following the eruption. It was clear immediately afterward (or as soon as one woke up, in some cases :p) that it was a disaster of immense proportions. But access was limited- roads were wiped out by the lahars- and dangerous. No one knew what was going to happen next, and aircraft mostly stayed some distance upwind from the mountain.

One issue that I clearly remember was the suggestion that an area much larger than the peak itself had erupted. In retrospect, the features that caused this rumor were phreatic blast craters: (via the CVO Photo Archives)
Spirit Lake, Pumice Plain, and phreatic explosions, soon after the May 18, 1980 eruption of Mount St. Helens. USGS Photograph taken on May 29, 1980, by Dan Dzurision.
These craters were the result of water seeping into the still-hot debris, and causing steam explosions. But I remember the news stations reporting "on-going eruptions" in the area where Spirit Lake had been. No one was even sure if the lake still existed. Here's the front page of "The Paper of Record" on that stunned Monday morning:
The "at least 8 dead" would ultimately rise to a tally of 57, and reading the article, I found myself repeatedly surprised at what was not known, or incorrectly believed.
The earlier ash and steam eruptions this year were dwarfed today, but it is not clear whether lava was being expelled in the absence of a lava eruption, the major worries were drifting ash, which is hazardous to crops, water supplies and health; forest fires, and flash floods resulting from melting glaciers.
Ash is a form of lava, and the statement, "it is not clear whether lava was being expelled in the absence of a lava eruption," is just bizarre to me. If there is an "absence of a lava eruption," it seems it would be a fair assumption lava isn't being expelled. But ash was being expelled, to the tune of nearly a third of a cubic mile. Not to be too mean about it, but this reporter didn't really have a clue. Still, I think the article, from a perspective of 30 years later, does a fine job of illustrating the confusion surrounding the situation in the days immediately following the eruption.

The Oregonian (OregonLive, in it's online incarnation) may have reposted the text of its May 19 stories; if so I haven't seen it. But even in the headline, which is all I can really read, the subtext of confusion is apparent...
Spirit Lake wasn't really gone, of course, but it had been displaced and obscured by the tremendous amount of debris an angry mountain had lobbed at it. Again, access, visibility, incorrect assumptions, and dubious conjectures made clear vision even more difficult than the ash did in those days of havoc. Incidentally, the Oregonian front page above was the one I had two copies of, one until it was too tattered to use as a wall poster anymore, and the other a treasured resident of my files for many, many years. I'm pleased to have another copy. It's from another magnificent large-format photo gallery at OregonLive. There is also a nice gallery of photos of the mountain, the visitor center, and surrounding communities taken this year. Below is another selection from the many mind-boggling pictures there. I still haven't been able to find any clips of even photos of the active lahars after the eruptions... lots from afterwards, but nothing that approaches the haunting mental images I have of the roiling mire, tossing six foot tree trunks around like toothpicks. This one conveys a sense of the difficulty presented by the muck.
Teresa Fiest, 16, gives a helping hand to Oregonian reporter Susan Hobart as the two make their way slowly to the home of Fiest’s brother-in-law. Photo credit: The Oregonian
So while I and many others marked yesterday as "the anniversary" of this event, the fact is that for many, "the event" would last for days, even weeks. And for 57, the event was the last thing they knew.

1 comment:

jeg43 said...

Stumbled over here yesterday from
and became a very interested reader. I've noticed your comments for some time at a couple of blogs I read on a regular basis and have appreciated your skill with the written word - don't know why I didn't get here sooner. You do a fine job!