Mount St Helens

About Mount St Helens

• It is a volcanic peak in the Cascade Range of southwestern Washington, United States of America.
• It is part of the larger Pacific Ring of Fire.
• The volcano was formed during four eruptive stages beginning about 275,000 years ago and has been the most active volcano in the Cascade Range during the Holocene.
• Its eruption on May 18, 1980, was one of the greatest volcanic explosions ever recorded in North America.

Key points about Pacific Ring of Fire

• It is also known as the Circum-Pacific Belt is a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes.
• Its length is approximately 40,000 kilometres (24,900 miles).
• It traces boundaries between several tectonic plates—including the Pacific, Juan de Fuca, Cocos, Indian-Australian, Nazca, North American, and Philippine Plates.

Q1) What are Tectonic plates?

These are large pieces of the Earth's lithosphere (the rigid outer layer of the Earth) that fit together like a puzzle, covering the entire surface of the planet. These plates are constantly moving, albeit very slowly, and their interactions at plate boundaries are responsible for a variety of geological phenomena, including earthquakes, volcanic activity, and the creation of mountain ranges.

Source: Mount St Helens: More than 400 earthquakes recorded since mid-July. It is a threat?