In a startling revelation it has been found that the reservoir of lava beneath Yellowstone National Park is at least twice as big as scientists previously thought. Some University of Utah Researchers say the lake of molten rock is at least two-and-a-half times larger than the previous estimate, with pictures showing the reservoir measuring 80km long and 20km wide.
Reported in Nature, geophysicist Robert Smith said: “I don’t know of any other magma body that’s been imaged which is so humungous.”
Scientists reported their finding at the annual meeting of the Geological Society of America in Denver, Colorado. Yellowstone is the largest super-volcano on the continent and has erupted several times in the last two million years.
If it was to erupt today, some scientists predict a cloud of plant-killing ash would affect areas up to 1,000 miles away, with two thirds of the US becoming uninhabitable.
Yellowstone is famous for its underground lava lake, which fuels the park’s hot springs. Most of the molten rock likes a few kilometres below Earth’s surface.
Jamie Farrell, a Utah University researcher, mapped the reservoir by analysing data from over 4,500 earthquakes: “Seismic waves travel more slowly through molten rock than through solid rock, and seismometers can detect those changes,” Nature reports.
Smith said earthquakes of magnitude seven or more are cause for more concern than an eruption as such. In 1959, a magnitude 7.3 earthquake that hit near Yellowstone killed 28 people.