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.
No actual volcanic eruption has occurred in the Yellowstone region for about 70,000 years. However, since the 1970s, scientists have detected significant changes in this remarkable volcanic and hydrothermal (hot water) system, including rapid ground uplift and subsidence and bursts of earthquake activity.