And there I was thinking my earthquake scientist husband, Ross would be satisfied walking sections of the Californian San Andreas Fault, and that’d be the closest we’d get to Plate Tectonic danger. But no, here we are driving straight towards an active volcano in Washington state.
Mount St Helens … she’s an astonishing sight, even from 100 klms away on the outskirts of Portland, Oregon. Rising from the horizon, a massive mountain, jagged and white-ridged with snow. As we drive closer it becomes obvious why a wide glacial creek is strewn with grey sediment, thousands of large rocks and scattered with dead tree trunks; and also why the top of the mountain is jagged.
In 1980, in the days preceding the May 18th eruption the mountain began to bulge from the side, like a magma boil simmered underneath, pushing up against the surface of her skin. Another concern were the series of earthquakes from under the mountain – ominous warnings. But there’d been small earthquakes before and nothing had happened.
Earthquake scientists flocked to view, study, experiment – never before had they been offered an opportunity like this. One scientist, 30-year-old David A. Johnston manned an observation post about 10 km from the volcano on the nearby Coldwater Ridge.
While many scientists thought the volcano would erupt from the top like others do, Johnston insisted the blast would be lateral and would originate from that bulge growing on the side of the mountain.
It did, and his last yells were captured on his radio …“Vancouver! Vancouver! This is it!”
Seconds later he was engulfed and swept away by a hot ash cloud of the lateral blast created by the collapse of the north flank. It was the largest landslide in recorded history and his camera would’ve captured that horrifying mass roaring down towards him. David Johnston’s body was never found.
When the volcano blew the top off the mountain on Sunday morning of May 18th, the collapse of the northern flank mixed with ice, snow, and water to create lahars (volcanic mudflows). The lahars flowed many miles down the Toutle and Cowlitz Rivers, destroying millions of pine trees and innumerable animal and birdlife; and taking fifty-seven lives; 250 homes, 47 bridges, 24 km of railways, and 298 km of highway. Beautiful Spirit Lake, once a top spot for water sports was covered in 150 ft of rock, ash and debris, its waters pushed out with such force they created two new lakes further down the mountain.
Thirteen hundred feet of Mount St Helens’ summit blasted away when the volcano erupted that morning. You may remember the television reports in 1980 with images of forests like bare matchsticks laid out all in one direction. Where heat and hot ash stripped every leaf from every tree as it smashed through. Twenty klms away, on the edge of the National Park the forestry plantations are growing again, but dead tree trunks and upturned roots are more visible as we drive into the Park.
Nearer the volcano the mountains are still bare, but there are signs of slow recovery – it’s almost 30 years. Scrubby mountain shrubs, mosses, lichens and a scattering of Douglas fir seedlings on slopes once thick with growth.
We stand on the ridge where David Johnston sat for the last time. It’s an observation post for earth scientists from all parts of the world now. These men and woman rarely make the news, they constantly battle for research funding and face Government cut-backs on staff. Many risk their lives daily in the field.
This observation post looking out across to the mountain also a National Park Visitor’s Centre. The Johnston Ridge Observatory is a fitting memorial to Dave Johnston, a brave, volcano-crazy scientist.
We are filled with awe.
P.S. Some fond memories of Portland, Oregon:
- Staying with Evelyn, vulcanist (who keeps an eye on the regions’ volcanoes – if anyone’s gonna know it’ll blow, it’ll be Evelyn)
- The day in the snow on Mt Hood, another volcano.
- Powell’s famous book store
- Jazz bars
- The city’s public transport – brilliant!