Highway from Hell: Volcano tears through 35km of crust in Weeks
Liquid hot magma from the Earth’s mantle can shoot up to the surface via a “highway from hell” over just a few weeks, volcanologists have discovered.
Boffins studying the Irazú stratovolcano in Costa Rica, and specifically its eruption between 1963 and 1965, found the first hard evidence of high-speed magma ascents. This proves volcanoes aren’t necessarily created over thousands of years.
The boffins found that deep, hot lava can rapidly set off an eruption like that of Irazú in the 1960s. This could help them to forecast future dangerous eruptions, they wrote in a new study.
“If we had had seismic instruments in the area at the time we could have seen these deep magmas coming,” said the lead author, Philipp Ruprecht of Columbia University’s Lamont-Doherty Earth Observatory. “We could have had an early warning of months, instead of days or weeks.”
Irazú, which is over 3,000m tall (10,000ft) and covers nearly 518km2 (200 square miles), and erupts around every 20 years or less, with varying levels of damage. Its eruption in 1963 went on for two years, killing at least 20 people and burying hundreds of homes in mud and ash.
The volcano sits on the Pacific Ring of Fire, where the oceanic crust is slowly sinking beneath the continents, producing some of the Earth’s most fiery explosions.
Boffins had thought that mantle magma feeding the eruptions sat around in a mixing chamber several miles under Irazú for long periods of time. But ash from the volcano’s prolonged blast is the latest to suggest that lava sometimes bypasses the chamber altogether, rushing over 20 miles to the surface in just a few months.
READ FULL: http://www.theregister.co.uk/2013/08/01/volcano_rapid_eruptions/