Meanwhile, the remaining magma stalls and freezes in place. Sometimes, the water flashes out explosively as in the case of Mount St Helens in 1980 or Mount Lassen in 1912. The water is the dominant "volatile", or the molecule that easily changes into gaseous form.Īccording to the study, the evolving magma in the Cascades rises into and through the crust, but does not make it to the surfaces because the water flashes out as the pressure from the overlying crust diminishes with ascent. The water in the rocks becomes part of the melt, as that ocean crust sinks into the Earth and partially melts. Also, the crust of the ocean is forced below the crust of the continent. The volcanoes in the Cascade Range are found in a place where Earth's tectonic plates are pushing toward each other. Characteristics Of Volcanoes In Cascade RangeĪlkalic volcanoes, which are rich in sodium and potassium, are very different from volcanoes such as those in the Cascade Range which extends from northern California through British Columbia to Alaska. The mountain is relatively poor in silica. Mount Erebus belongs to a family of volcanoes with an alkalic chemical composition, with lavas relatively rich in sodium, potassium and other elements including Earth's rare elements. In 1908, Sir Ernest Shackleton and his teammates became the first persons to ascend Mount Erebus. Mount Erebus, Antarctica's only active volcano, and its dormant companion volcano, Mount Terror, were named after the exploring ships of Sir James Ross, who discovered them and the Transantarctic Mountains in 1841. Wannamaker added that understanding both water and carbon dioxide volcanoes is important for calculating the budget of such volatile gases deep in the Earth that involves injection of material into Earth's mantle and its return to the surface to start all over again. Rift volcanoes form when magma rises into the gap between diverging plates. Graham Hill, the lead author on the paper, said that Mount Erebus is an example of a carbon dioxide-dominated rift volcano, a complement to the more widely known arc volcanoes of the Pacific Rim and elsewhere, dominated by water.Īrc volcanoes are a chain of volcanoes, hundreds to thousands of miles long, that form above a subduction zone, which is the area of collision between two of Earth's tectonic plates, where one plate sinks into the mantle underneath the other plate. Mount Erebus Is Carbon Dioxide-Dominated Rift Volcano Phil Wannamaker, the second author on the paper, said the study expands on researchers' understanding of the sources and transport of diverse types of magma and volatile gases to the surface. The study was recently published in the journal Nature Communications. Antarctica contains examples which define the spectrum of Earth's volcanic processes, and which represent a key piece of the puzzle for understanding global continental evolution.Ī new study, conducted by researchers at University of Utah and University of Canterbury New Zealand has explained how carbon dioxide deep underground helps magma avoid being trapped deep in the Earth, and allows it to reach and pool the surface, resulting in the formation of lava lakes. New Delhi: The Antarctic continent has long been a land of mystery and heroic achievements made famous by the explorations of James Ross, Roald Amundsen, Robert Scott, and Ernest Shackleton.
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