Disclaimer: I'm no Danish teaching expert, I just happen to be an Icelander who was forced to learn Danish as my second language - and although I always got very good grades in Danish, I was never good in Danish: can't speak it, can't understand a Dane - I can maybe read it a little bit...
University of Utah geology and geophysics professor Fan-Chi Lin said the blob-shaped lower magma reservoir in Earth's lower crust is located 12 to 28 miles (20-45 km) under Yellowstone, with a volume of 11,500 cubic miles (46,000 cubic km), or 11.2 times the volume of Arizona's Grand Canyon.
The lower reservoir, which has a volume of 11,200 cubic miles, measures about 30 by 44 miles and is about 16 miles thick. Even if the next explosion is many thousands of years away, Yellowstone's cavernous heat tanks poke up an occasionally surprise. The last lava flow was some 70,000 years ago, USGS says.