Ring of Fire

The Hawaiian shield volcanoes are the largest mountains on Earth.
The May 18, 1980 eruptive column at
Before May 18, 1980, Mount St. Helens' summit altitude of 9,677 feet made it only the fifth highest peak in Washington State.
During the 9 hours of vigorous eruptive activity, about 540 million tons of ash fell over an area of more than 22,000 square miles.
The eruptive history of Mount St. Helens (Washington) began about 40,000 years ago with dacitic volcanism, which continued intermittently until about 2,500 years ago.
The major peaks in the US part of the Cascade Range are (from north to south) Mount Baker, Glacier Peak, Mount Rainier, Mount St.
The principal volcanoes of the Hawaii Islands (from northwest (oldest) to southeast (youngest)) are Niihau, Kauai, Oahu, Molokai, Lanai, Maui, Kahoolawe, and Hawaii (Big Island).
Several lofty volcanic peaks dominate the Cascade Range of the Pacific Northwest; the principal part of the range extends from
There are a few historic examples of simultaneous eruptions from volcanoes or vents located within about 10 km of each other, but it's very difficult to determine whether one might have caused the other.
On May 18, 1980, at Mount St.