Kind: captions Language: en [Music] Yellowstone National Park contains one of our country's favorite landmarks but it's actually a warning signal going off every hour now we're [Music] going wow that's roaring man love that this is old [Music] faithful that's what they call geyser what we're seeing is superheated water and steam blowing out of the ground it's been doing this for 100 years plus and it's a really reliable tourist attraction because the thing goes off like clockwork it's one of the most powerful geysers in the world capable of shooting 8,500 gallons of superheated water as high as an 18 story building it's a constant reminder that lurking beneath the surface is a ticking Time Bomb you see although it may not seem like it I'm actually standing on top of a volcano and park geologist Hank heasler wants to show me what it looks like underground this is a threedimensional model this is a magma chamber a mass of semi- Molen Rock reaching almost 1500° F it's the powerhouse of a volcano that's uh one of the larger chambers that have been mapped in the world wow but can we agree that we'd like to keep it down there I don't think we have a choice it's going to do what it wants to do together with a second recently discovered magma chamber there's enough partially molten rock under Yellowstone to fill the Grand Canyon 13 times over and scientists believe below them lies a mantle plume a column channeling heat from the Earth's core melting the Rocks above and creating the massive magma Chambers under Yellowstone if this super volcano ever erupted we'd be in trouble there's a place in Nebraska where you can see just how bad things could get inside this plain steel Barn is a 12 milliony old animal Pompeii [Music] here are the fossilized skeletons of 200 animals mostly rhinos and horses lie Frozen in the exact position in which they died the man who discovered this site is paleontologist Mike Vorhees we found remains of of more than 50 species of animals 12 million years ago go our Wildlife was similar in richness to the east African savanas of today the gray dust that in TMS these animals is what killed them ash from a massive volcanic eruption there was so much of it that the air was polluted and animals had to breathe dust for weeks and weeks and weeks and they ended up dying by the thousands and the mantle plume that we think made this super volcano is still around our continent has been sliding over this hot spot which has triggered numerous eruptions and now it sits beneath Yellowstone so the plume under our most famous National Park is a repeat offender that will strike again it's hard to imagine that much volcanic ash and yet we know that this kind of an event has happened before and almost certainly it will happen again a super eruption in Yellowstone would be a really bad day for North America as a geologist I'd love to see this thing erupt but as a North American not so [Music] much it would rank as the most violent event since humans first set foot on the [Music] continent