Mount Mazama and Crater Lake: Growth and destruction of a Cascade volcano

Fact Sheet 092-02
By: , and 



For more than 100 years, scientists have sought to unravel the remarkable story of Crater Lake’s formation. Before Crater Lake came into existence, a cluster of volcanoes dominated the landscape. This cluster, called Mount Mazama (for the Portland, Oregon, climbing club the Mazamas), was destroyed during an enormous explosive eruption 7,700 years ago. So much molten rock was expelled that the summit area collapsed during the eruption to form a large volcanic depression, or caldera. Subsequent smaller eruptions occurred as water began to fill the caldera to eventually form the deepest lake in the United States. Decades of detailed scientific studies of Mount Mazama and new maps of the floor of Crater Lake reveal stunning details of the volcano’s eruptive history and identify potential hazards from future eruptions and earthquakes. 

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Publication type Report
Publication Subtype USGS Numbered Series
Title Mount Mazama and Crater Lake: Growth and destruction of a Cascade volcano
Series title Fact Sheet
Series number 092-02
DOI 10.3133/fs09202
Edition Online Version 1.0
Year Published 2002
Language English
Publisher U.S. Geological Survey
Contributing office(s) Volcano Science Center
Description 4 p.
Country United States
State Oregon
Other Geospatial Crater Lake, Mount Mazama
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