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Exploring USGS volcano observatories—Part 3: CA

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Mount Shasta, a steep-sided Cascade Range stratovolcano in Northern California, looms above Little Glass Mountain, a thick obsidian flow erupted from the Medicine Lake shield volcano about 1,000 years ago. These are just two of the 19 young volcanic areas monitored by the USGS California Volcano Observatory (CalVO). INSET: USGS-CalVO staff, shown here in the observatory's operations center in Menlo Park, CA, oversee research and monitoring on volcanoes in California and Nevada. Margaret Mangan (far right), who worked at the USGS Hawaiian Volcano Observatory in 1990-1998, is now CalVO's Scientist-in-Charge. USGS photos.