Mt. St. Helens Renewal Slow, Steady

first_imgThis is an eyewitness report of ecological renewal at the volcano that erupted 32 years ago.This past Saturday, August 4, a group of about 60 people hiked the Johnston Ridge trail to view Mt. St. Helens and hear about its geology and ecology.  The event, advertised on, was organized with help from members of the Design Science Association of Portland and 7 Wonders Museum on highway 504 west of Mt. St. Helens.  The event featured geologist Dr. Steven A. Austin, who personally researched the volcano in the weeks and years after its May 18, 1980 eruption and has hiked the area numerous times.  Dr. Austin had even scuba-dived into Spirit Lake to view the patterns of tree deposition after sonar his team towed under a boat revealed trees sinking into the bottom in upright positions, analogous to the petrified forests of Specimen Ridge.  He also discovered a 1/4oth scale “miniature Grand Canyon” carved by a mudflow in 1982.  This canyon (left center in photo) was the destination of the hike.Renewal at Mt. St. HelensGeology:  The volcano is very stark, with most of the surroundings still highly impacted by the eruption 32 years ago.  Two deep gorges, Loowit Canyon, headed with a large waterfall, and Step Canyon, 600 feet deep, descend from the crater and flow into the North Fork of the Toutle River.  Mudflow damage along this river is still visible for miles west Mt. St. Helens.  In the vast landslide debris field below the crater, the “Little Grand Canyon” becomes visible after about 1.5 miles on the trail.  In many ways (except for color) the 200′ deep canyon resembles its larger namesake: it has stratified layers, round-headed side canyons and sharp gullies entering from both sides.  There is a small stream flowing through it reached after a descent down Truman Trail, after 4.6 miles of hiking (requires off-trail permit).What makes this little canyon fascinating and relevant to catastrophist geology is that we know exactly how and when it formed.  The main eruption on May 18, 1980 deposited a thick layer of landslide debris.  In June, a pyroclastic flow deposited 25 feet of sediments that show remarkable laminations at both large and small scales – a surprise to pre-eruption geological thinking.  Finally, on March 19, 1982, a mudflow that poured from the crater deposited mud on top of the other flows, then overtopped a debris dam, causing rapid downcutting and upstream cutting through the three layers.  While it might appear that the stream carved the canyon, we know from this highly-monitored volcano that the stream is a mere relic that had nothing to do with the canyon’s rapid, catastrophic formation.Ecology:  The blast zone north of the volcano still looks very desolate, especially south of Johnston Ridge.  Fallen trees remain all over the hillsides many miles from the crater, bearing mute testimony to the power of the eruption that flattened virgin forest in seconds.  Pioneer species are making a strong foothold, especially nitrogen-fixing lupine and alder.  Remarkably, some seeds and small animals survived the blast under snowfields and were able to re-establish small populations.  A few douglas fir saplings dot the landscape in places.  Elk herds are among the first large mammals that have entered the blast zone, living on grasses and vegetation growing on plateaus alongside the Toutle River canyons and debris hummocks.  Some birds and frogs inhabit the riparian environment along the stream in Little Grand Canyon.  There is very little shade, though, in the blast zone.Spirit Lake is 200 feet higher than its pre-eruption level.  The landslide on May 18, one of the largest ever witnessed, caused a water wave 860′ high that swept a million logs into the lake onto a new bed of debris.  So covered was the lake with logs and pumice from the blast, early reports claimed Spirit Lake had been obliterated entirely.  The heat and vegetation brought into the water created conditions for rapid growth of anaerobic bacteria, causing an opaque, churning stew of gases and germs.  Ecologists were surprised at how quickly the lake rebounded, however.   The water is blue and mostly clear.  Trout were probably illegally reintroduced by a tourist, since it is questionable they could have found their way in naturally.  They are doing well, after subsiding from record growth rates when first  introduced into the uncompetitive environment.  About 35% of the logs remain, mostly douglas fir that could float for decades more.  Snowmelt over the post-eruption years caused rapid rise in lake levels that threatened another catastrophic dam breach down the North Toutle drainage, so engineers carved a tunnel over a mile long to divert the excess water down Coldwater Canyon.It’s quite humbling to look at this environment that all changed so quickly on March 18, 1980.  Our guides told us that in places where we were walking along the ridge and in the valley, we would have been in the sky before the eruption, looking down on the tops of old-growth forest. The volume of material lost to the once-conical volcano is very striking, even as seen from airliners leaving Portland; it’s like the mountain was sliced horizontally, with a huge gash on the north side where the lateral eruption unleashed its energy.  And yet this was a small eruption as volcanoes go.Mt. St. Helens is important as a living laboratory of rapid geology and ecological succession.  Textbooks on geology and ecology had to be rewritten because of the events that followed that fateful morning (for example, see Science Daily article today).  Dr. Austin’s work is proof against the accusation that creationists only criticize evolution without offering original research.  To the contrary, his work, unfettered by Lyellian presuppositions, has been generally well received and has influenced secular geologists to reconsider the role of rapid catastrophic change.  The evidence he uncovered and published is second to none.  Moreover, his winsome Christian manner, alongside the quality of his research, has gained the respect of notable geologists willing to think outside the box.Several of our guides also believe that God, showcasing his power through this event, also showed mercy in providential timing of the eruption.  It could have destroyed much of Portland had the blast aimed in that direction instead of north, and would have killed many more people on the north side had it occurred the day before or after that Sunday morning, because the prior day property owners were allowed to come in and get their belongings, and the day after a new group of campers and sightseers would have come within the actual (not predicted) danger zone.  The 57 who were killed were all forewarned of the danger; now, Spirit Lake Lodge owner Harry A. Truman and the others are fossilizing under tons of sediments.  Solomon said, “Boast not thyself of tomorrow, for thou knowest not what a day may bring forth.”  (Account, photo and commentary by David Coppedge.) (Visited 98 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img

Leave a Reply

Your email address will not be published. Required fields are marked *