[caption id="attachment_81151" align="aligncenter" width="640"] The northeastern part of Yellowstone Caldera, with the Yellowstone River flowing through Hayden Valley and the caldera rim in the distance[/caption]
Yellowstone Supervolcano 2.5X Larger Than Previously Believed
The supervolcano beneath the surface of Yellowstone National Park is 2.5 times larger than previously believed according to a study from the University of Utah.
The supervolcano is part of what is known as a caldera, an underground volcano forming a shape like a cauldron. More accurate details about the caldera were discovered by measuring the seismic waves of the underground magma which is anywhere from 3 to 9 miles beneath the surface of the earth. The length of the caldera is 88.5 km (~50 miles) with a width of 29 km (~18 miles). The lead author of the study, Jamie Farrell, claims the quantity of lava in the supervolcano is enough to give rise to what would be among the top three eruptions over the past 2.1 million years.
So just how spectacular would the eruption be? For a comparison, let's go back to the year 1980 when the United States Geological Survey (USGS) refused to take no for an answer any compelled the city of Mount St. Helens to close off access to the nearby volcanic mountain of the same name and evacuate the town.
The volcano erupted with devastating effect which would have killed thousands of residents.
[caption id="attachment_81150" align="alignright" width="420"] Earthquakes in Yellowstone National Park from 1973 to Sep 2012.
I (Kelvin Case (talk)) created this work entirely by myself. I combined File:Yellowstone earthquakes.jpeg with University of Utah Earthquake Information Center data posted on-line. (Click to enlarge)[/caption]
An 80,000 ft. plume of volcanic ash arose which was sufficient to pass through the troposphere and well into the stratosphere. Now, multiply that by 2,000 times and that would be the impact of this supervolcano. Its volcanic ashes would wrap around the planet and mark a global event in size and damage.
The national park and surrounding communities would be annihilated, while plants and entire farms hundreds of kilometres away would be wiped out. Escape would be futile — ash damages commercial aircraft engines, making flight hazardous.
Sulfur entering the upper atmosphere would turn to sulfur dioxide, circle the globe and drop temperatures. Worldwide famine would likely ensue.
“There’s not a whole lot you could do,” said Jamie Farrell with the department of geology and geophysics at the University of Utah.
“Once this thing revs up, there’s nothing you can do to stop it.”
Farrell is the lead author of a study presented at the American Geophysical Union Fall Meeting in San Francisco in December that determined the magma chamber beneath the Yellowstone caldera is 88 km long and 29 km wide, reaching depths up to 15 km. That makes it the largest imaged magma reservoir in the world.
But is an eruption in the cards? No one really knows.
“There may not be, but there probably will be. Of course, we don’t know when,” Farrell said
Park officials did not immediately reply to emails for comment.
[caption id="attachment_81149" align="aligncenter" width="560"] At Yellowstone and some other volcanoes, some scientists theorize that the earth's crust fractures and cracks in a concentric or ring-fracture pattern. At some point these cracks reach the magma “reservoir,” release the pressure, and the volcano explodes. The huge amount of material released causes the volcano to collapse into a huge crater—a caldera." From nps.gov[/caption]
Magma chamber under Yellowstone’s supervolcano more than two times larger than previously believed