Cascade Volcanic Arc
TheCascade Volcanic Arc(also known as theCascadesor theCascade Range) is a major range ofvolcanoesin southwesternBritish Columbia,Washington,Oregon,and northernCalifornia.
The arc is central to theCascade Range,a mountain range in thePacific Northwest.It includes about 20 major volcanoes, among over 4,000 separate volcanic vents.[1]
Twelve volcanoes in the arc are over 10,000 ft (3,000 m) in height, and the two highest,Mount RainierandMount Shasta,are over 14,000 ft (4,300 m). By volume, the two largest Cascade volcanoes are the broad shields ofMedicine Lake VolcanoandNewberry Volcano,which are about 145 mi³ (600 km³) and 108 mi³ (450 km³) respectively.
The volcanism in the arc began about 37 million years ago, but most of the present-day Cascade volcanoes are less than 2 million years old. The most recent major catastrophic eruption in the arc was atMount St. Helenson May 18, 1980.
The major volcanoes in the arc includeMount Silverthrone,Mount Meager,Mount Cayley,Mount Garibaldi,Mount Baker,Glacier Peak,Mount Rainier,Mount St. Helens,Mount Adams,Mount Hood,Mount Jefferson,Three Sisters,Broken Top,Mount Bachelor,Newberry Volcano,Mount Thielsen,Mount Mazama(Crater Lake),Mount McLoughlin,Medicine Lake Volcano,Mount Shasta,Mount TehamaandLassen Peak.
References
[change|change source]- ↑Madson J.K.et al2006. Cenozoic to Recent plate configurations in the Pacific Basin: Ridge subduction and slab window magmatism in western North America.42(1).Geological Society of America.pp. 27, 28, 31.
- Harris, Stephen L. 2005.Fire mountains of the West: the Cascade and Mono Lake volcanoes.3rd ed, Mountain Press Publishing Company.ISBN978-0-87842-220-3