The eruption of Mount St. Helens at 8:32 on May 18, 1980 was a major geological event that continues to have many effects on the 150 square miles surrounding the volcano. This eruption is classified as the worst volcanic disaster in United States history. In this explosion, the mountain lost its conical tip and 1,300 feet in elevation. Fifty-seven people and hundreds of animals lost their lives.Know More
Native Americans living in the area before the first Europeans crossed the United States to the area presently known as Washington State recognized the fiery potential of the mountain. However, a period of dormancy from 1857 until the 1980 eruption had led people to lay aside any fears of the mountain. The homes they had built at the base of the volcano were destroyed when the volcano erupted. In addition, the eruption caused serious economic hardship for many in the area.
The eruption began with an earthquake that also started an avalanche. In just minutes, rock and debris traveled into Spirit Lake and 14 miles down the Toutle River. A plume of ash shot hundreds of feet into the air. While locals reported not hearing any noise with the eruption, its sound was heard in Montana and California. Ash from the volcano filled the air for weeks following the eruption, affecting all of Washington as well as surrounding states.Learn more about Volcanoes
Mount St. Helens is a cinder cone volcano that formed through the gradual accumulation of cinders and ash at the base of the mountain. Unlike a shield volcano, such as Mauna Loa in Hawaii, cinder cones can rise sharply from the surrounding terrain and maintain a steep, angular profile throughout their existence.Full Answer >
Mount St. Helens has erupted numerous times in its 300,000-year history, most notably on May 18, 1980. While much of its early history remains a mystery, geologic studies have concluded that Mount St. Helens is the most active volcano in the Pacific Northwest.Full Answer >
The most recent volcanic eruption of Mount St. Helens in Washington State, which began in October, 2004, produced hot, but solid, extrusions of smooth-sided lava called "spines." The extrusion of the solid lava spines continued until January 2008, producing more than 120 million cubic yards of solidified lava. Unlike the previous and catastrophic eruption, which occurred in 1980 and produced thick lava flows, the eruptions occurring between 2004 and 2008 produced only solid lava extrusions and resulted in no loss of life or property.Full Answer >
Mount St. Helens, an active stratovolcano, has an elevation of 8,363 feet. It is located in Skamania County, Wash., in the Pacific Northwest region of the United States.Full Answer >