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Novarupta [a] is a volcano that was formed in 1912, located on the Alaska Peninsula on a slope of Trident Volcano in Katmai National Park and Preserve, about 290 miles (470 km) southwest of Anchorage. Formed during the largest volcanic eruption of the 20th century, Novarupta released 30 times the volume of magma of the 1980 eruption of Mount St ...
The Alaska-Aleutian Batholith may extend under the volcano. [10] An aeromagnetic anomaly overlies Aniakchak; similar anomalies are found on neighboring volcanoes but also on much older plutonic complexes in the region. [49] During the last glacial maximum more than 11,700 years ago, the region was covered by ice.
It was probably triggered by the entry of new basaltic magma into an older basaltic andesite magma body under Cone D [188] left stranded there for the past 1,000–2,000 years. [189] Interaction with water from the lake north of Cone D [ 190 ] and groundwater made the eruption cloud water-rich, and thus difficult to detect by remote sensing ...
The Wrangellia terrane, as one of the largest in Alaska formed beginning 300 million years ago in the Pennsylvanian and built up with basalt, carbonate and phyllite during the Triassic (these rocks are exposed from the Alaska Range to the Wrangell Mountains). Originating as a volcanic island arc, Wrangellia exhausted its magma supply and began ...
Previous research using seismology found that a large reservoir of magma sat beneath the caldera. However, the recent study, using a method known as magnetotellurics that tracks the electric ...
Subglacial eruptions, those of ice-covered volcanoes, result in the interaction of magma with ice and snow, leading to meltwater formation, jökulhlaups, and lahars. Flooding associated with meltwater is a significant hazard in some volcanic areas, including Iceland, Alaska, and parts of the Andes.
Espenberg is a volcanic field in Alaska that contains the largest maars on Earth.It was active during the Pleistocene until 17,500 years BP, when a large eruption formed the 8 by 6 kilometres (5.0 mi × 3.7 mi) wide Devil Mountain Maar and deposited tephra over 2,500 square kilometres (970 sq mi), burying vegetation and forming the largest maar on Earth.
Magma that is extruded as lava is extremely dry, but magma at depth and under great pressure can contain a dissolved water content in excess of 10%. Water is somewhat less soluble in low-silica magma than high-silica magma, so that at 1,100 °C and 0.5 GPa , a basaltic magma can dissolve 8% H 2 O while a granite pegmatite magma can dissolve 11% ...