Mount St. Helens

Mount St. Helens

Mount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is part of the Cascade Volcanic Arc, a segment of the Pacific Ring of Fire that includes over 160 active volcanoes. Mount St.Helens is most notorious for its major eruption on May 18, 1980, the deadliest and most economically destructive volcanic event in US history. Fifty-seven people were killed; 250 homes, 47 bridges, 15 miles of railways, and 185 miles of highway were destroyed.

About Mount St. Helens in brief

Summary Mount St. HelensMount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. The volcano is located in the Cascade Range and is part of the Cascade Volcanic Arc, a segment of the Pacific Ring of Fire that includes over 160 active volcanoes. Mount St. Helens is most notorious for its major eruption on May 18, 1980, the deadliest and most economically destructive volcanic event in US history. Fifty-seven people were killed; 250 homes, 47 bridges, 15 miles of railways, and 185 miles of highway were destroyed. The mountain is 6 miles across at its base, which is at an elevation of 4,400 feet on the northeastern side and 4,000 feet elsewhere. The nearest community to the volcano is Cougar, Washington. The average annual rainfall is 140 inches, and the snow pack on the mountain’s upper slopes can reach 16 feet. The Lewis River is impounded by three dams for hydroelectric power generation. The southern and eastern sides of the volcano drain into an upstream impoundment, the Swift Reservoir, which is directly south of the peak. The largest of the dacite domes formed the previous summit, and off its northern flank sat the smaller Goat Rocks dome. Both were destroyed in the 1980 eruption. During the 1980 winter, a new glacier appeared along the Gifford Pinchot National Forest along the Lewis River, 11 miles south-southwest of the summit.

The glacier is less than 50 miles to the southwest of the mountain and is located along the Toutle River on the north and northwest, the Kalama river on the west, and the LewisRiver on the south and east. It is the only glacier in the U.S. that can be seen from the air. The peak rose more than 5,000ft above its base. It stood out prominently from surrounding hills because of the symmetry and extensive snow and ice cover of the pre-1980 summit cone, earning it the nickname, by some, \”Fuji-san of America\”. The peak is 34 miles west of Mount Adams, the nearest major volcanic peak in Oregon, is 60 miles southeast of Mount St St Helens. It formed only within the past 40,000 years, and it is considered the most active in the Cascades within the Holocene epoch. These volcanic mountains are approximately 50 miles from Mount Rainier, the highest of Cascade volcanoes, and are the nearest volcanoes to the city of Seattle. The summit cone began rising about 2,200 years ago, and is about 6 miles across at the base, where the lower flanks merge with adjacent ridges. The tallest peak in the mountain is Mount Adams at 8,363 ft (2,400 ft) The nearest volcano to the east is Mount Hood, 60 miles south of Seattle, which has a similar name.