Volcanoes vary in size from small cinder cones that stand only a few hundred feet tall to the most massive mountains on earth.
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Article 1: Cinder Cones
Cinder cones are typically simple volcanoes that consist of accumulations of ash and cinders around a vent. Sunset Crater Volcano and Capulin Volcano are cinder cones. Read more
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Article 2: Composite Volcanoes (Stratovolcanoes)
Composite volcanoes are made up of both lava flows and pyroclastic deposits and usually experience multiple eruptions over long periods of time. Mount Rainier is a composite volcano. Read more
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Article 3: Shield Volcanoes
Shield volcanoes are typically very large volcanoes with very gentle slopes made up of basaltic lava flows. Mauna Loa and Kilauea in Hawaii Volcanoes National Park are shield volcanoes. Read more
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Article 4: Calderas
Calderas are large collapse features that can be many miles in diameter. They form during especially large eruptions when the magma chamber is partially emptied, and the ground above it collapses into the momentary void. Crater Lake and Aniakchak Crater are calderas. Read more
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Article 5: Explosive Calderas
Explosive calderas result from violent eruptions of great quantities of silicic magmas. These eruptions produce massive eruption columns that extend into the stratosphere, and voluminous pyroclastic flows. Eruptions that produce explosive calderas generally range from 6 (Colossal) on the Volcanic Explosivity Index (VEI) to 8 super eruptions (Apocalyptic). Read more
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Article 6: Summit Calderas
Summit calderas form on preexisting composite volcanoes that experience VEI 6-7 eruptions that cause their summits to collapse. Summit calderas may become filled with precipitation to form steady-stake lakes, although these lakes may also be drained if the caldera rim becomes breached. Read more
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Article 7: Resurgent Calderas
Resurgent calderas are substantially larger than summit calderas with diameters of many tens of miles (kms). Although they form in areas that have previously experienced volcanism, they do not form on any preexisting volcanic edifice. VEI 7-8 eruptions lead to caldera formation. Read more
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Article 8: Older Caldera Complexes
The presence of voluminous ash-flow tuffs are one of the main markers for the presence of older caldera complexes. Subsequent erosion and/or volcanic activity can make their caldera walls hard to find. Most of the older caldera complexes in or near national park sites are very large and were of the resurgent type. Read more
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Article 9: Nonexplosive Calderas
Nonexplosive calderas are located at the summit of most large shield volcanoes, like Kīlauea and Mauna Loa in Hawai’i Volcanoes National Park. They form during VEI 0-1 (Effusive to Severe) eruptions that drain the shallow magma chambers located beneath them. Nonexplosive calderas can contain pit craters, which are smaller collapse structures, as well as lava lakes that can be active for periods of time. Read more
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Article 10: “Super Volcanoes”
"Supervolcanoes" are very large calderas that have had eruptions at magnitude 8 on the Volcanic Explosivity Index (VEI), meaning that they erupted more than 240 cubic miles (1,000 cubic km) of magma. Yellowstone has had two "supervolcano" eruptions. Read more
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Article 11: Volcanic Domes
Lava domes are steep-sided rounded accumulations of highly viscous silicic lava over a vent. Some domes are part of composite volcanoes, but large ones can make up their own volcanoes. Lassen Peak is a dome. Read more
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Article 12: Maars and Tuff Rings
Maars and tuff rings are low-standing pyroclastic cones with large craters that usually form from highly-explosive eruptions caused by the interaction of magma with ground or surface waters. Ubehebe Crater in Death Valley National Park is a maar. Read more
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Article 13: Fissure Volcanoes
Fissure volcanoes erupt from elongated vents (fissures) rather than a central vent. The lava flows in Craters of the Moon National Monument were erupted from fissures. Read more
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Article 14: Monogenetic Volcanic Fields
Monogenetic volcanic fields are areas covered by volcanic rocks where each of the volcanic vents typically only erupt once. Monogenetic volcanic fields typically contain cinder cones, fissure volcanoes, and/or maars and tuff rings. They also usually encompass large areas covered by basaltic lava flows. Read more