00:00what if yellowstone erupted today yellowstone is not a typical volcano it is a caldera system
00:07the collapsed crater at its center measures 45 kilometers by 75 kilometers the magma chamber
00:14below it holds enough material to qualify as a super volcano volcanic explosivity index 8
00:21the maximum category it has erupted three times in the last two and a half million years
00:272.1 million years ago 1.3 million years ago and 640 000 years ago each eruption buried
00:36significant portions of north america under ash and was among the largest volcanic events in earth's
00:42recent history if it erupted today the explosion would send a column 50 kilometers into the
00:48stratosphere within minutes the sound would be audible across the continent every aircraft in
00:54northern hemisphere would be grounded within hours volcanic ash destroys jet engines on contact
01:01within 48 hours 10 centimeters of ash would cover every surface within 1500 kilometers
01:08roads would be impassable power lines would collapse under the weight
01:14crops in the field would be buried and killed the ash zone would extend from the rocky mountains to the
01:20mississippi river but the ash is not the primary long-term threat what matters is the sulfur dioxide
01:26yellowstone would inject hundreds of millions of tons of sulfur dioxide into the stratosphere there it
01:32reacts with water vapor to form sulfate aerosols these aerosols act as a reflective shield bouncing sunlight
01:40back into space before it can warm the surface global temperatures drop between 5 and 10 degrees celsius
01:47that is the volcanic winter the first growing season fails across the northern hemisphere temperatures fall
01:54below the threshold for most grain crops the second season fails the third global food reserves are
02:01typically sufficient for about 90 days a three-year disruption of northern hemisphere agriculture would push
02:08over 1 billion people into severe food shortages the precedent exists 74 000 years ago the toba super volcano in
02:19what is now indonesia erupted
02:22genetic evidence from human dna suggests the human population collapsed to perhaps 10 000 breeding individuals
02:30the volcanic winter lasted approximately a decade the modern agricultural system did not exist
02:37it would not survive toba happening now yellowstone is monitored continuously satellite systems track ground deformation
02:46to millimeter precision a dense network of seismometers records thousands of small earthquakes each year
02:54the science is honest an eruption is not imminent but the geological interval between eruptions has not been exceeded
03:03the system is active the eruption lasts days the aftermath lasts decades that is what sits under a national park
03:11what do you think
