Mount St. Helens was formed about 275,000 years ago and has been the most active volcano in the Cascade Range, northwest US, during the Holocene (roughly the last 12,000 years of Earth’s history). Historical eruptions in the 19th century were witnessed by early settlers. Prior to 1980, the mountain had the shape of a conical, youthful volcano sometimes referred to as the Mount Fuji of America. But on 27 March 1980 and thereafter, it suffered a series of volcanic explosions, culminating on 18 May with a major explosive eruption. The upper 400 m of the summit was removed by a huge debris avalanche, leaving a horseshoe-shaped crater now partially filled by a lava dome and a glacier.
Some 57 people as well as thousands of animals were killed directly, hundreds of square miles were reduced to wasteland, and damage was calculated at over $1 billion - it was the most disastrous volcanic eruption in US history. Subsequently, the US Forest Service took over control of the area, which has been preserved, in an unaltered state, as the Mount St. Helens National Volcanic Monument. Further information can be found at Wikipedia, USGS, and Encyclopaedia Britannica.
Four days after the catastrophic event, President Jimmy Carter visited the site, and he wrote about the visit at some lengthy in his diary. Since then, and over the decades, he refused repeated requests to publish his account. Only now - forty years after the eruption - has he made the unedited diary entry public. Here is journalist Jim Erikson - who said the eruption was the biggest story he ever covered - explaining how access to Carter’s diary entry inspired him to complete a book about the volcano:
‘In January 2019, I began reading clips of my stories from the Tacoma News Tribune, as well as other volcano articles from the Oregonian and the Columbian, the only newspapers I had access to during the weeks I spent in Vancouver, Washington, with geologists. In February I wrote a letter to President Carter in Plains, Georgia, including a copy of my story about his visit to the volcano to establish my credibility. My request was for his memories. After a month and a half, Carter did respond, giving me permission to use his diary entry for the day of his 1980 visit. I was elated. It inspired me to contact all the other people I interviewed for my book. I collected photos to augment the book and was pleased when The History Press accepted my proposal.’
And here is Carter’s diary entry. (In fact, an edited version of this diary entry appears in Carter’s own published work: White House Diary - see Googlebooks. Also, see the online version of Carter’s ‘Presidential Daily Diary’ for 22 May 1980 here.)
22 May 1980
‘In the morning, about 5:30, we ran 3 miles or so. And then took helicopters. Went down the Columbia River to the Kelso area where the Toutle and Cowlitz Rivers dump into the Columbia. The surge of ash carried by the rivers had clogged up the Columbia ship channel from a depth of 40 feet down to only 12 feet. We are moving hopper dredges in there as quickly as possible to get the channel opened up because a number of ships are trapped in the Portland harbor and need to get a load of cargo out.
We then went up to Toutle Valley in the helicopter - first seeing large quantities of white-looking ash. And in the narrow river valley, we eventually began to see where the blast had directly burned the trees. Fifteen miles from the volcano, the trees had been burnt instantaneously with power at least equivalent to a 10-megaton nuclear explosion. The blast that followed in a few minutes had leveled every tree in an area of 150 square miles. One cubic mile off the side of the mountain had been pulverized, most of it into ash the consistency of face powder. Less than one micron in particle size. This ash had flowed down the mountain, carrying large chunks of ice, and also large rocks and molten lava.
Spirit Lake, the head of the Toutle River, was filled with 400 feet of ash and lava. The level of it had been raised 150 to 200 feet. And there was a dam 12 miles long below the lake.
This is nothing like I had ever seen. It was much worse than any photographs of the face of the moon. It looked like a boiling cauldron, because large icebergs the size of houses from the glaciers on the mountain were buried underneath hot ash and lava. The icebergs were melting and the surface of the ash was caving in.
The steam from the melting ice was rising. There were a few fires visible, but there was nothing much left to burn.
Eighty-five or 90 people were either dead or missing, including, unfortunately, some geologists who were handling the seismograph stations and instruments to assess the mountain’s volcanic activity before it erupted.
The top 1,200 feet of the mountain was missing.
We couldn’t get all the way to the mountain because of heavy steam and cloud formations. When the helicopter pilot decided to turn around, he didn’t get any argument from me.
After a press conference [in Portland], we went to Spokane. Although they only had about a half-inch deposit of ash, being 250 miles away their airport was closed [it remained so for twenty-two days] because this extremely fine powder couldn’t be controlled and was suspended in the air.
At other places around Yakima and Ritzville the ash was as deep as 4 or 5 inches, and they’re still not able to shovel their way out through this fine powder which has a specific gravity of about 2.7. It is non-toxic, and will ultimately be incorporated into the soil or on the bottom of lakes and streams, or carried out to sea.
Frank Press [Carter’s science advisor] says this is by far the biggest natural explosion ever recorded in North America in the last 4,000 years.
Only because the volcano was very closely monitored, was the loss of life restricted. And, of course, it is in an isolated area, as well.
My inclination is not to clean up anything we don’t have to, that’s not directly effecting human life, but to let nature take its course in the valley region and around the mountain, which has a completely different geological configuration now.’