Advertisement
On May 18, 1980, a magnitude 5.1 earthquake started the largest landslide in human history at Mt. St. Helens. The pressure on the magma in the volcano caused the gases to expand and the magma just exploded. The explosion blasted a mix of hot gases, lava and rocks of all shapes laterally from the top side of the volcano at about 300-500 mph. The wind force sheared all the ancient forests in its way. There are stumps still standing but the trees were blown far from this area. The ash from the explosion rolled out vertically in a dark flume as high as 80,000 feet in the stratosphere. It melted all the glaciers on the mountain creating floods and mudslides called lahars as far as the Columbia River about 50 miles away. Most communities in central and eastern Washington lay under about an inch of ash and the skies were darkened even in midday. There were 57 people who lost their lives in this eruption. Many smaller eruptions have occurred since 1980 and lava domes are building inside the crater. Prior to the May 18, 1980 eruption the bulge on the side that erupted swelled about 7 feet a day filling
with magma. Geologists are watching these domes for increased activity. The valley floor that was scorched and dredged by this volcano has gained new life in the last 41 years. Boulders that flew from the volcano dammed up rivers which had to be opened up due to flooding. Now the river is running freely through the valley, already carving out its impression on the landscape. With the sea of pine forest gone there is more grazing for the mountain goats and other mammals. There are trees growing now in the area but not as the pictures pre eruption. There was a 30 year old geologist who was monitoring the mountain for seismic activity the morning of the eruption, his name was David Johnston. He radioed in when the explosion happed and said “Vancouver This is it!” Those were his last words. The Johnston Observatory in the Mt. St. Helens National Monument is named for him. It does not open until later in May so we could not tour the observatory. They did have a nice self guided interpretative trail with excellent views into the crater of the volcano. It sits at about 4500 feet and there was still some snow
in places and the volcano was covered in snow. The mountain prior to the eruption was 9677 feet and after the eruption it is 8365 feet. You can see the stumps left from the explosive winds and the devastation the volcano can emit. We did see a herd of mountain goats grazing on the mountain side close to the observatory. It gives a new meaning to respect the mountain.
Advertisement
Tot: 0.043s; Tpl: 0.013s; cc: 7; qc: 23; dbt: 0.0213s; 1; m:domysql w:travelblog (10.17.0.13); sld: 1;
; mem: 1mb
Jan
non-member comment
Beautiful!
This is so beautiful, mountain goats are great!