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Pavlof Volcano

Photo: A cloud of ash above a volcano
Pavlof Volcano blasts clouds of ash and steam to a height of about 18,000 feet (5,490 meters) over the Alaska Peninsula during an August 2007 eruption. Pavlof is the most dangerous type of volcano—a stratovolcano—with the potential for highly explosive eruptions. Stratovolcanoes tend to form where one of the Earth’s tectonic plates descends below another.
Photograph by Chris Waythomas/Alaska Volcano Observatory/U.S. Geological Survey

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