(Express) – Scientists are closely monitoring a 465-mile-long piece of molten rock rising below the Yellowstone caldera, a bombshell documentary has revealed. The supervolcano, located in Yellowstone National Park, has erupted three times in history – 2.1 million years ago, 1.2 million years ago and 640,000 years ago. Volcanoes typically blow when molten rock, known as magma, rises to the surface following the Earth’s mantle melting due to tectonic plates shifting.

However, geologists have revealed how Yellowstone’s magma chamber, which sits on top of the magma plume, is slowly rising each year. Should it continue at this rate, it is possible magma could break through the Earth’s crust – forming flowing lava, it was revealed on YouTube’s “Why the Yellowstone supervolcano could be huge”. The 2015 mini-documentary detailed: “Scientists have new data that gives them a better picture of Yellowstone’s underground plumbing. READ MORE