What is Cascade Volcanic Arc?
[[File:Cascade Volcanic Arc.jpg|thumb|right|300px]] [[File:Cascade eruptions during the last 4000 years.png|thumb|350px|Major Cascade volcano eruptions in the last 4000&nbsp;years]] The '''Cascade Volcanic Arc''' (also known as the '''Cascades''' or the '''Cascade Range''') is a major range of [[volcano]]es in southwestern [[British Columbia]], [[Washington]], [[Oregon]], and northern [[California]]. The arc is central to the [[Cascade Range]], a mountain range in the [[Pacific Northwest]]. It includes about 20 major volcanoes, among over 4,000 separate volcanic vents.<ref>Madson J.K. ''et al'' 2006. 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.</ref> Twelve volcanoes in the arc are over 10,000&nbsp;ft (3,000 m) in height, and the two highest, [[Mount Rainier]] and [[Mount Shasta]], are over 14,000&nbsp;ft (4,300 m). By volume, the two largest Cascade volcanoes are the broad shields of [[Medicine Lake Volcano]] and [[Newberry Volcano]], which are about 145&nbsp;mi³ (600&nbsp;km³) and 108&nbsp;mi³ (450&nbsp;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 at [[Mount St. Helens]] on May 18, 1980. The major volcanoes in the arc include [[Mount Silverthrone]], [[Mount Meager]], [[Mount Cayley]], [[Mount Garibaldi]], [[Mount Baker]], [[Glacier Peak]], [[Mount Rainier]], [[Mount St. Helens]], [[Mount Adams (Washington)|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 Tehama]] and [[Lassen Peak]]. == References == {{reflist}} *Harris, Stephen L. 2005. ''Fire mountains of the West: the Cascade