Why the Yellowstone Supervolcano Could Be Huge
Transcript
00:00 Recently, scientists have collected new data,
00:03 giving them a better picture of Yellowstone's
00:06 underground plumbing.
00:08 Right beneath the caldera from the last eruption
00:12 sits the magma chamber.
00:13 And it's fed by a plume of magma stretching down 465 miles
00:22 northwest into Montana.
00:25 It's mostly solid rock with the potential to liquefy.
00:31 And scientists are closely monitoring it.
00:34 Magma, or molten rock, is rising through the plume
00:38 into the magma chamber at 2 inches a year.
00:43 There's no reason for it to stop,
00:45 although it might come in spurts.
00:47 Our images show wider parts and narrower parts,
00:50 so it's like slugs of material that
00:53 are flowing in a sewer line.
00:55 And this restless Yellowstone caldera
00:57 is truly living, breathing.
01:00 Every once in a while, it burps.
01:01 The danger is if the plume starts liquefying and moving up
01:09 at a faster rate.
01:10 Natural systems can throw us a lot of curveballs.
01:14 A lot of things can happen that we're not really ready for.
01:18 Scientists Jake Lowenstern is looking for a pattern
01:21 connecting the supervolcano today
01:23 and its three prior major eruptions, 2.1 million years
01:29 ago, 1.3 million years ago, and 640,000 years ago.
01:36 In two of the really large eruptions at Yellowstone,
01:40 so much material comes out, entire mountain ranges
01:43 end up falling into the ground and essentially disappearing.
01:46 One 50-mile stretch of mountains simply
01:49 disappeared by collapsing into the magma chamber.
01:53 [music playing]
01:56 University of Toronto geologist John Westgate
01:59 has tracked the ash from Yellowstone's prior eruptions.
02:04 It covered much of the United States.
02:07 It occurs right out of the Pacific Ocean.
02:10 It's even found in the Gulf of Mexico.
02:12 Up in Northeast Montana, there's a site that we're working on.
02:16 The temperature is over 7 meters thick.
02:20 These eruptions are enormous.
02:22 The amount of material erupted from them, huge.
02:26 When Mount St. Helens erupted in May 1980,
02:30 it blew off one side of the mountain
02:32 and triggered an avalanche of snow, mud, ash, and rock.
02:36 [music playing]
02:39 Driven by the wind, the ash landed in 11 states
02:43 and up into Canada.
02:45 But that's nothing compared to the amount of ash
02:48 from Yellowstone's last three major eruptions.
02:52 In magnitude and volume, each one
02:55 was far greater than Mount St. Helens.
02:57 [music playing]
03:01 Today, there's little evidence of the supervolcano's
03:04 violent past.
03:07 The 50 by 30-mile caldera from the last eruption
03:11 was covered by lava and ash and smoothed over by glaciers.
03:15 [music playing]
03:18 Forests now conceal the scars.
03:22 [music playing]
03:25 (upbeat music)
03:28 [MUSIC]