|About the Site|
|Mt. St. Helens National Volcanic Monument|
The Mt. St. Helens National Volcanic Monument was created to commemorate one of the most explosive geological events in the U.S.'s recorded history--the eruption of Mt. St. Helens in 1980. This event represented the first eruption of a volcano in the continental United States since Mt. Lassen's series of eruptions from 1914-1917. The monument, established in 1982, consists of 110,000 acres around the mountain and is administered by the U.S. Forest Service (rather than the National Park Service, custodian of national parks and monuments).
Mt. St. Helens, first spotted and named by George Vancouver in 1792, is a relatively young volcano. Its earliest eruptions occurred approximately 40,000 to 35,000 years ago. As a young volcano, it was quite beautiful, surround by dense forests, lovely mountain lakes, and was nearly symmetrical and relatively uneroded by glaciers. It had last erupted 123 years before. The bottom part of the mountain, with the now broken summit obscured by clouds, can be seen in the picture below.
On March 20, 1980, a 4.1 level earthquake rocked the area, beginning the series of events which led to the ultimate eruption. On March 27, a small eruption blasted steam and ash 7,000 feet into the sky. By April 27, a large bulge in the north face of the mountain had been noted. Landowners and visitors began to be evacuated from the area. On May 8, a larger eruption occurred, sending ash and steam 13,000 feet into the air. While many expected a more violent eruption would soon occur, few were prepared for what happened later in the month.
On May 18, 1980, at 8:32 A.M., a 5.1 magnitude earthquake occurred, causing a portion of the north face of the volcano to slide. This triggered an enormous eruption which lasted for nine hours, sent material 13,000 feet in the area, and blew away a large portion from the top of the mountain. The view in the picture below shows the northeastern portion of the mountain, with the crater and the remaining part of the mountain visible in the top portion of the picture.
The eruption blew off the top 1300 feet of the mountain. A crater 1.2 miles wide by 2.4 miles long remained. The crater itself is shown in a closeup view below, partially visible through the clouds.
The most serious effects of the eruption resulted from a tremendous lateral blast. A very hot mass of rock, ash, and ice raced north from the crater at 600 miles per hour, devastating everything in its path. Some idea of the effects of this tremendous force can be seen below. This pictures, taken from Windy Ridge northeast of te mountain and showing the view immediately north of the mountain, was a heavily forested area before the eruption. Every tree and all other living things were destroyed. Much of the fallen timber has been reclaimed, but the sense of desolation remains.
The blast followed the contours of the land. Trees were knocked over up to six miles north of the volcano, up and down the slopes of the hills, as can be seen below.
Beyond the immediate blast zone the hot eruptive cloud left trees standing but killed them and burnt off limbs and needles. Two views below show the edge of this area.
The impact of the eruption was not predicted and was difficult to believe. An avalanche dumped material 14 feet deep into the channel of the North Fork of the Toutle River for 14 miles, creating a devastating flood. One half cubic miles of debris were ejected from the volcano, creating ash-induced darkness throughout the eastern part of Washington state. 235 square miles north of the mountain were utterly devastated. 57 people lost their lives. The Columbia River temporarily became impassible to ocean-going vessels headed to Portland, Oregon. And 5,000 black-tailed deer, 1500 Roosevelt elk, 15 mountain goats, and 300 black bears also perished. Through the summer and fall of 1980 5 more eruptions occurred, but none matched the impact of events of May 18.
Nowhere were the devastating effects of the eruption more evident than at Spirit Lake. This pristine lake was surounded by dense forests, several lodges, and was a favorite destination for inhabitants of northern Oregon, southern Washington, and elsewhere. Lying immediately to the north of the mountain, it was directly in the path of the lateral blast. In addition to the leveling of the surrounding forests, the lake was covered with woody debris, and had its levels of bacteria raised and oxygen depleted dramatically. The picture below shows a portion of the north end of the lake; under the "Devastation" heading above is a picture of the north end. The lake is almost unrecognizable from its pre-eruption appearance.
The most poignant aspect of the blast was the disappearance and probable death of 83 year-old Mt. St. Helens Lodge owner Harry Truman. A resident of the area for nearly 50 years, the salty, colorful old man became nationally famous before the eruption for his refusal to leave his lodge despite the orders for all residents and visitors to clear the danger area. He was permitted to remain, but the blast covered his lodge with 180 feet of debris and 90 feet of water. Truman, although frightened, had expected lava flows from which he could be evacuated by helicopter. What happened was something entirely different.
Below is another view of the lake, which has demonstrated a remarkable recovery, and is now relatively clean and productive. In both the picture above and below the covering of logs which still remains on a portion of the lake can still be seen.
In the aftermath of the eruption much of the area north of the mountain looked like somewhere on the moon. Trees lay like matchsticks strewn across the landscape, green vegetation was completely absent, and much of the ground was covered by ash and pumice. However, the area has seen an amazing recovery in the more than 15 years since the eruption. Many small animals actually survived the eruption by virtue of their dens and burrows beneath the ground. Pumice has eroded away in many places and soil returned to the serface. Plants and trees have begun to return to even the most devastated areas. The sort of recovery which is occuring can be seen in the picture below in which the remants of the eruption--dead trees, pumice, etc.--are mixed in with new growth. The area is slowly beginning to turn green again.
Even the mountain is rebuilding itself, as a sizeable lava dome has been growing since shortly after the original eruption.
Below is a picture a little further away from the immediate blast zone, showing just how much recovery has occurred in some areas.
The Mt. St. Helens area has undoubtedly been devastated many times before the recorded history of the area. The beautiful setting which eixted before the 1980 eruptions is proof of the recovery powers of nature.
Information about Mt. St. Helens has been drawn from personal experience, data available in the park itself, and a number of other sources, including:
- Corcoran, Thom. Mt. St. Helens: The Story Behind the Scenery. Las Vegas, NV: KC Publications, 1985.
- National Geographic's Guide to the National Parks of the United States. National Geographic Society, 1992.
- Quiring, James P. Mt. St. Helens: The Continuing Story. Las Vegas, NV: KC Publications, 1991.
- Rosen, Shirley. Truman of St. Helens: The Man and His Mountain. Bothell, WA: Rosebud Publishing, 1981.