Mega eruption of Yellowstone's southern twin

BREAKING EARTH SCIENCE NEWS
March 28, 2006
"Vilama Caldera formed during a single event that emitted approximately 2000 cubic kilometers (almost 500 cubic miles) of pyroclastic material," said geologist Miguel M. Soler of the National University of Jujuy in San Salvador de Jujuy, Argentina. The volume of ash and pyroclastic material, called ignimbrites, produced by the 8.4 million-year-old eruption, and the size of the associated caldera, put it among the world's largest known eruptions, he says. "In contrast, for example, Yellowstone produced its important volumes of ignimbrites and lavas in three cataclysmic events. Eruptions at 2.0, 1.3, and 0.6 million years ago ejected huge volumes of rhyolite magma, and each formed a caldera and extensive layers of thick pyroclastic flow deposits," said Soler. Soler will present some of the recent groundbreaking work on Vilama supervolcano on Monday, 3 April 3 at Backbone of the Americas - Patagonia to Alaksa. The meeting is co-convened by the Geological Society of America and the Asociación Geológica Argentina, with collaboration of the Sociedad Geológica de Chile. The meeting takes place 3-7 April in Mendoza, Argentina. The Vilama Caldera appears to have been created when the 10 by 24-mile roof catastrophically collapsed on a chamber of molten rock, or magma, explosively venting vast amounts of ignimbrites out in various directions. That massive roof collapse is the one thing all large calderas have in common and what separates them from the exponentially smaller "single vent" volcanic eruptions like Mount St. Helens or Mount Pinatubo.

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Vesuvius found to be more dangerous than was thought
DPA , ROME Tuesday, Mar 14, 2006,Page 6
Researchers have found evidence of a catastrophic eruption by Mount Vesuvius some 4,000 years ago which devastated the area of present-day Naples for centuries afterward.
The finding, published in the latest issue of the Proceedings of the National Academy of Science of the United States, provides today's disaster planners with a new "worst-case scenario."
It had previously been believed that the volcano's worst eruption was the notorious one of 79 AD which wiped out the Roman cities of Pompeii and Herculaneum.
But according to experts an eruption 3,780 years ago was more destructive.
Well-preserved remains of a prehistoric village were found about 15km northeast of Vesuvius, where volcanic deposits captured quickly abandoned domestic scenes. Outlines of huts and skeletons of pregnant goats were preserved by the high-speed surges of hot volcanic ash and gases, and researchers found a skeleton of a man and woman buried under 1m of pumice outside the village.
About 15km north-northwest of Vesuvius, thousands of human and animal footprints solidified in cooling ash were found.
Their path indicates a massive, rapid evacuation out of the devastated area.
Giuseppe Mastrolorenzo and Michael Sheridan say their findings represent an important "step forward in our knowledge of Vesuvius."
They note that while the Pompeii eruption had suggested that the area north of Naples was not at risk, the Old Bronze Age eruption suggests all areas surrounding the volcano could be affected.