There is a circular region that surrounds the Pacific Ocean where volcanic activity is particularly high. This is known as the “Ring of Fire” and includes coastal areas in Japan, Russia, Alaska, Canada, Oregon, Washington state, California, Mexico, Southeast Asia, and many South Pacific islands. The ring stretches some 40,000 miles (64,000 kilometers) and includes three-fourths of the planet’s volcanoes. Among those are Mt. St. Helens and recently active volcanoes in Alaska, such as Mount Spur, which erupted in 1992, and Mt. Redoubt, which erupted March 22, 2009, near Anchorage.