The Snake River Valley, over millions of years, it is estimated that there were 12 eruptions, about half as much as previously thought. However, they were probably more powerful than the colossal events that have occurred in Yellowstone.
We know that the last eruption of Yellowstone was a catastrophic event. But now we know that it was only part of a series of numerous super traces of which are in the form of burnt tracks left along the Snake River to the east from Oregon to Yellowstone – said the study’s lead author, volcanologist from the Department of Geology at the University of Leicester.
A new study found that this eruption of a series of recently opened super intense magma tic activity period Yellowstone 8-12 million years ago, it was the largest and strongest of the prior art. And this is only the first of a projected series , – he added.
Scientists came to this conclusion in the course of hard work. They investigated and collected the crumbs of abundant evidence, including widespread deposition of glassy fused with the landscape. Magnetic, mineralogical and chemical properties of these deposits are perfectly preserved, which allowed them to detect at great distances. In addition, the researchers took samples by drilling from the bottom of rocks, consisting of ancient volcanic ash.
Super defined as Castle ford Crossing, occurred about 8.1 million years ago. It is estimated that its volume exceeded 1900 cubic kilometers (456 cubic miles). That would be enough to fill one of the Great Lakes – Ontario.
The strength of the eruption is estimated at about 8.6 on a scale of Volcanic Explosive Ind ex. This means that it was hundreds of times more powerful than the eruption of Mount Pinatubo in the Philippines in 1991, which had a VEI 6, and 10 times more powerful than the eruption of Mount St. Helens in Washington state in 1980.
The chains of volcanoes gradually make their way east to Yellowstone, where 640,000 years ago, the eruption of the Yellowstone caldera formed. The most recent eruption at Yellowstone was 170,000 years ago, and the last lava flow running down its slopes about 70 000 years ago.
Despite periodic alarms about the devastating consequences of another eruption in Yellowstone Park, we argue that this is impossible. The epicenter of the volcano is now moved by the thickness of the North American lithosphere plate, that is, for its eruption will take much more energy and heat than when he was in a thin and loose layer under the Snake River Plain, – said the researcher Bob Smith of the University of Utah, who studied aerodynamics Yellowstone for 60 years.