Mount St. Helens Eruption (1980)

The Mount St. Helens eruption in Washington state in 1980 was the most shocking and damaging volcanic eruption that the continental United States has ever experienced. Preceded for months by earthquakes and other activity, the volcano finally erupted on May 18, 1980, killing 57 people. Many animals, flora, and other wildlife were also killed in the eruption. After dealing with the volcanic activity, the country had to focus on recovering from the incredibly destructive event, and decide upon the disaster relief that could be done. This disaster affected many aspects of life, including real estate losses, business disruption, and personal problems stemming from the disaster.

Mount St. Helens is located 45 miles west of Mount Adams. The two volcanic mountains, considered to be “brother and sister,” are located in the western part of the Cascade Range, each approximately 50 miles from Mount Rainier, the highest of the Cascade Mountains. Compared with the other Cascade Mountains, Mount St. Helens is geologically young, being formed only in the past 40,000 years. Mount St. Helens's pre-volcano summit cone began rising 2,200 years ago. Mount St. Helens was the fifth-highest peak in Washington before the 1980 eruption, with an elevation of 9,677 feet.

Although humans have lived near Mount St. Helens for thousands of years, written and oral records exist only since 1800. In 1800, an eruptive period began that lasted for 57 years and was named after the Goat Rocks dome. The Goat Rocks period began with a dacidte tephra explosion, then experienced an andesite lava flow, and ended with the positioning of a dacite dome, which was displaced by the 1980 eruption. The 1800 eruption in all likelihood rivaled the 1980 eruption in size, although it did not significantly change the position of the mountain's cone. Between 1831 and 1857, there were at least a dozen small eruptions of Mount St. Helens, although none of significance until the disaster of 1980.