Volcanic activity during the past 2,000 years in the Western United States.

Cascade volcanoes

Volcanoes of the Cascade Range erupt far less frequently than Kilauea and Mauna Loa, but they are more dangerous because of their violently explosive behavior and their proximity to populated and cultivated areas in Washington, Oregon, and California. The 1980 eruption of Mount St. Helens in southwest Washington dramatically illustrated the type of volcanic activity and destruction these volcanoes can produce. Scientific studies of the eruption of Mount St. Helens and the eruptive histories of other Cascade volcanoes continue to improve public awareness and understanding of these potentially dangerous peaks.

In contrast to Kilauea, Cascade volcanoes erupt a variety of magma types that generate a wide range of eruptive behavior and build steepsided cones known as composite volcanoes. In addition to basalt, andesite and dacite magmas are common.

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Maintained by John Watson
Updated 06.24.97