No. It's over twice the size! The supervolcano that lies beneath Yellowstone National Park in the US is far larger than was previously thought, scientists report. A study shows that the magma chamber is about 2.5 times bigger than earlier estimates suggested. A team found the cavern stretches for more than 90km (55 miles) and contains 200-600 cubic km of molten rock. The findings are being presented at the American Geophysical Union Fall Meeting in San Francisco. http://www.bbc.co.uk/news/science-environment-25312674 It hasn't blown for 650,000 years but is currently active. Should we be worried?