Volcanologists believe a Yellowstone
supereruption would bury large swaths of Colorado, Wyoming and Utah in up to three feet of toxic volcanic ash.
For Yellowstone, that type of
supereruption last happened more than 600,000 years ago, after magma filled the empty chambers below the Earth's surface some decades before it blew.
The lowered position of the mandible, in combination with the reduction of the occlusal forces, can allow a
supereruption of the posterior teeth, with increased height of the palatal vault and the development of an anterior open bite.
Ambrose, "Volcanic winter in the Garden of Eden: the Toba
supereruption and the late Pleistocene human population crash," in Symposium: Catastrophism, Natural Disasters and Cultural Change, World Archaeological Congress 4, University of Cape Town, 1999.
Giant blobs of magma appear underground and then pour onto the surface within centuries, suggests a new study of a California
supereruption.
For example, he sees the
supereruption of Mount Toba as nearly wiping out humans.
Fortunately, there is no large-scale ground deformation or greatly increased seismic or geyser activity that signals an impending
supereruption. Given the rarity of these cataclysms, we're probably safe for tens of thousands of years.
Another
supereruption took place in Yellowstone 2.1 million years ago.
However, despite the claims of those who fear 2012, there's no evidence that such a
supereruption is imminent.
A team of researchers headed by ETH-Zurich professor Carmen Sanchez-Valle has now identified a trigger for
supereruptions by determining the density of supervolcanic magma, using an X-ray beam at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France.
'Short of a meteor impact, these
supereruptions are the worst environmental hazards our planet can face,' Gregg said.