The Yellowstone caldera has been dubbed a supervolcano due to its capability to inflict global devastation should another supereruption occur in future. This has already happened three times in history – 2.1 million years ago, 1.3 million years ago and 640,000 years ago, leading to fears that it is “overdue” another mammoth eruption due to the average time between previous activity. The United States Geological Survey (USGS) says these claims are unsubstantial but still constantly watch the seismographs around Yellowstone National Park for signs of anything out of the ordinary.