Vaporized blood, crushed in an earthquake, being buried under tons of ash, or just being cooked live in a flow of hot lava? How would a supervolcano actually kill you?
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00:00Vaporized blood, crushed in an earthquake, being buried under tons of ash, or just being
00:06cooked live in a flow of hot lava.
00:08How would a supervolcano actually kill you?
00:11Defining a supervolcano isn't easy.
00:14The controversial term only really took off after a 2005 docudrama called Supervolcano
00:19dramatized the aftermath of an eruption in Yellowstone National Park.
00:24This, after all, is not only how life ends, it's also how life begins.
00:30Most volcanologists agree that a volcano becomes a supervolcano when it can potentially reach
00:35level 8 of the Volcanic Explosivity Index, or VEI.
00:39The second qualification is if it can produce over 1,000 cubic kilometers of material, like
00:44volcanic ash.
00:46Adding to the confusion is the fact that supervolcanoes are not bound to erupt in devastating fashion.
00:51Broadly speaking, volcanic eruptions can be put on a scale.
00:55Effusive volcanoes are relatively low-energy, like the ones that create large, sloping shield
01:00volcanoes such as Hawaii's Kilauea.
01:03Eruptive volcanoes have more explosive power, such as the destructive Plinian eruptions,
01:08named after Romans Pliny the Elder, who died in the AD 79 eruption of Mount Vesuvius, and
01:14his nephew Pliny the Younger, who later wrote about the eruption.
01:17But what if the worst-case scenario happened today?
01:20What if an especially large supervolcano, such as the one sitting beneath the Yellowstone
01:25Caldera, were to suddenly and explosively erupt?
01:28The consequences of this event could be nothing short of disastrous, and would affect humans
01:32the world over.
01:34It's difficult to pin down the precise time that a volcano of any sort will erupt, but
01:39certain precursors hint strongly at a coming blast.
01:42The movement of magma toward the Earth's surface can produce telltale signs like bulging of
01:47the ground, increased levels of volcanic gases, and odd temperature changes.
01:51Perhaps the most dramatic precursor of all would be the earthquakes, and they wouldn't
01:55be mild, either.
01:57Increased activity in a large reservoir of magma could spell more frequent and intense
02:02quakes, especially as all of that melted rock moves closer and closer to the surface, as
02:07U.S. geological survey scientist Jacob Lowenstern told Vox.
02:11The tremors would also serve to break up the ground above the entire looming magma chamber,
02:16making it easier for the molten rock and pent-up gases to reach the surface for miles around
02:20the volcano.
02:21Hopefully, this would also afford scientists the opportunity to warn the public and get
02:26an evacuation moving in time, though it would probably be a massive undertaking never before
02:31seen in history.
02:33It's hard to say exactly how a blast from a supervolcano would turn out, but things
02:37could get pretty spectacularly awful.
02:40The supervolcano currently sitting beneath Yellowstone National Park is a good example.
02:44If that magma chamber suddenly burst open, the shockwave emanating from the epicenter
02:49might kill 90,000 people alone, and that's before all the actual volcanic material reaches
02:55them.
02:56Smaller eruptions hint at the sort of shockwaves that a big one could produce.
03:00In January 2022, a submerged volcano located within the territory of Tonga, named Hungatonga
03:06Hungaha'apai, erupted, causing a sound that could be heard from Alaska to New Zealand.
03:11While it produced a large, deadly tsunami, the volcano also created a pressure wave so
03:16immense that it bounced around the Earth for days.
03:19Speaking with the New York Times, physicist Mark Boslow compared the wave to a staggeringly
03:24large sonic boom that encircled the planet, known to researchers as a Lamb Wave, after
03:29mathematician Horace Lamb.
03:31Previously recorded Lamb Waves came courtesy of nuclear weapons testing.
03:35The last known volcano to have a similar worldwide effect was Indonesia's Krakatoa, whose 1883
03:41eruption was so intense that sailors on a British ship 40 miles from the volcano suffered
03:47ruptured eardrums from the shockwave.
03:49The captain of that ship wrote that the blast was so immense he thought that perhaps Armageddon
03:53had occurred.
03:55Krakatoa offers up some of the best real-world evidence of what a large supervolcano might
04:00do to the hearing of people who were nearby.
04:03Even witnesses thousands of miles away could hear the blast.
04:06People typically reported that the eruption sounded like large artillery firing in the
04:10distance.
04:11This is the longest sound a wave has been known to travel from its source to a human
04:15ear.
04:16The Krakatoa eruption was incredibly powerful, spewing forth material at supersonic speeds
04:21and obliterating its island.
04:23The tsunami generated by the explosion killed anywhere from 36,000 to 120,000 people.
04:30The sound alone still stands as the loudest noise ever recorded.
04:34Despite all this, Krakatoa is not considered to be a supervolcano.
04:39Its explosivity only comes in at a 6 on the Volcanic Explosivity Index, while a supervolcano
04:45could erupt more quietly, such as with an oozing lava flow.
04:49One that blasts forth as a violent Plinian eruption could be seriously loud.
04:55Supervolcanoes are sitting on top of a lot of magma.
04:57Just how much depends on the volcano.
05:00The Yellowstone Caldera sits atop two large reservoirs of magma.
05:04The magma chamber closest to the surface sits as little as 3 miles beneath the top
05:09and is an estimated 55 miles long by 25 miles wide.
05:14Geologists originally estimated that only about 15% of that rock is in melted magma
05:19form, but a 2022 study increased that number to about 20%.
05:24The lower magma chamber is more than 4 times larger and sits between 12 to 30 miles deep,
05:30but just 2% of its reserves appear to be melted.
05:33This still represents a tremendous amount of superhot molten rock, but it might not
05:38be the massive underground cauldron of your worst nightmares.
05:41Most estimates conclude that a Yellowstone eruption would produce more than a square
05:45kilometer of lava.
05:47Though past lava flows have been fairly slow, one in today's park would incinerate plants
05:52and buildings, cover roads, and make it all but impossible to access parts of Yellowstone.
05:58All of that lava, ash, superheated gas, and other material that can spew forth from a
06:03supervolcano has to come from somewhere, and while a plume of toxic material hurtling
06:08into the sky or along the slope is sure to catch your attention, there's also the empty
06:12magma chamber left underneath the spewing volcano to worry about.
06:16During large eruptions, that chamber quickly loses the support of the molten rock it once
06:20contained, potentially becoming an unstable, hollow cave which might collapse in on itself.
06:26Anything on the surface would be brought down in a catastrophic tumble, forming a crater
06:30called a caldera.
06:32Sometimes calderas fill with water, creating large lakes that people might not realize
06:37were once the site of a humongous volcano.
06:39The Toba caldera in Indonesia is now a lake.
06:43In fact, it's the largest known lake to have been formed by a volcano, containing more
06:47than 58 cubic miles of water and reaching as deep as 1,656 feet.
06:53The biggest caldera anyone appears to have found is underwater.
06:57Known as the Apolaki caldera, it sits in the Philippine Sea of the island of Luzon.
07:02It's estimated to be a staggering 93 miles across.
07:06The eruption that formed this beast occurred about 41 million years ago.
07:11While there are plenty of things to worry about if you're in the path of a volcano,
07:15one hazard is extra terrifying.
07:18Pyroclastic flows
07:19A pyroclastic flow is a mass of volcanic material like ash, rock, and gas that comes barreling
07:25down the site of a volcano at intense speeds ranging from 50 mph up to over 430 mph.
07:33Because this mass of material is often dense and can top 1,300 degrees Fahrenheit, anything
07:39in its path is pummeled and incinerated into oblivion.
07:43This is exactly what killed most of the people who died during the eruption of Mount Vesuvius.
07:47A 2018 study found that people sheltering in seaside boathouses had been hit by a sudden
07:53and intense wave of heat soon after the eruption followed by a fast-moving pyroclastic flow.
07:59This was based on evidence left behind in skeletons which showed residue from the rapid
08:03vaporization of blood which were preserved by a dense bed of ash.
08:07A supervolcano could produce enough explosive power and material to create a pyroclastic
08:13flow which could extend as far as 62 miles from the epicenter of the eruption.
08:18Rock waves, earthquakes, blasts of heat, and pyroclastic flows aren't all though,
08:23and relatively speaking those threats don't even make it that far.
08:27Not so for the ash produced by a supervolcano which can be blasted high into the atmosphere
08:32allowing the material to spread out over a massive range.
08:36Volcanic ash also contains sharp bits of material making it tough and mildly corrosive.
08:41Because it becomes conductive when wet, ash can also disrupt electronics.
08:45The sheer amount of ash can be a big deal.
08:48An eruption of the Yellowstone supervolcano could produce so much ash that structures
08:52as far as 60 miles away would collapse under the weight.
08:56The fine ash can enter air filters and vehicle engines, complicating evacuation efforts and
09:01attempts to bring supplies into the region.
09:03According to a 2014 study published in Geochemistry, Geophysics, Geosystems, evidence of ancient
09:09Yellowstone eruptions indicates that volcanic material made it as far as the Gulf of Mexico.
09:15Depending on the length and intensity of a future eruption, practically everyone in
09:19the United States and its neighboring countries would be dealing with the widespread and disruptive
09:24ash.
09:25In addition to covering everything and ruining machines, volcanic ash can irritate your upper
09:30respiratory tract and can present serious problems for anyone with pre-existing breathing
09:34conditions.
09:35Very fine ash with a high silica content can present an even bigger and more long-term
09:40breathing problem, as it can scar lung tissue and lead to a disease known as silicosis.
09:46It's not like ash from your backyard barbecue.
09:49It's rock.
09:51It's abrasive, it's pervasive, it's destructive.
09:55That's not all.
09:56It can also irritate the eyes and skin of sensitive people.
10:00And then there's the problem with sulfuric acid, which can be produced when water in
10:03the atmosphere binds with volcanic sulfur dioxide gas.
10:07This can lead to a decrease in air quality that could set in motion long-lasting health
10:12issues.
10:13According to a 2019 study published in Epidemiology, the late 18th century eruption of Iceland's
10:18Laki volcano set into motion a complicated series of events that lowered temperatures
10:23and increased levels of air pollution for Europe and beyond.
10:27Pregnant people appear to have been put under greater stress by the results of this eruption,
10:31leading to a lower birth rate and greater infant mortality in Sweden for years after
10:36the eruption.
10:38And then there's the mud, which can't be taken lightly.
10:41The Park Service says lahars are the number one volcanic hazard that can affect people
10:45living below Mount Rainier.
10:47Known as a lahar, the mixture of water and volcanic debris that is produced by an eruption
10:52can move downhill in excess of 100 miles per hour, becoming larger as it goes by collecting
10:57more material.
10:59Depending on the landscape, a volcano can trigger a lahar by eruption beneath or near
11:03a lake, or by melting ice and snow on its peak.
11:07Rainfall soon after an eruption can also form fine volcanic ash into a lahar.
11:12The threat of a lahar can last long after the eruption, as the changed landscape may
11:16not be able to contain rainfall and debris as it once did, resulting in regular flooding
11:21and recurrent lahars.
11:22These mudslides can crush buildings, block roads, and kill anyone who is unlucky enough
11:27to be in the way.
11:29A supervolcano eruption can be so mighty that it could drastically change that of the
11:34entire planet.
11:35The 1991 eruption of Mount Pinatubo in the Philippines shot an estimated 15 million tons
11:41of sulfur dioxide into the upper atmosphere.
11:44For the next two years, those volcanic gases reflected and absorbed sunlight, contributing
11:49to planet-wide cooling by about one degree Fahrenheit at its peak.
11:53Dramatic as that effect was, Pinatubo is not considered to be a supervolcano, only reaching
11:59six on the VEI.
12:01A sufficiently large eruption of the Yellowstone supervolcano would likely have an even more
12:06noticeable effect on the global climate, though it's hard to say precisely what it would do.
12:10The lower temperatures created by an atmosphere loaded with volcanic ash and sulfur dioxide
12:15could harm agricultural production and put food insecurity and famines at the top of
12:20everyone's mind.
12:22Toxic acids like hydrogen halides produced by an eruption can also damage food crops
12:26and put a dangerous dent in the global food supply.
12:30While a supervolcano might contribute to global cooling, sometimes called a volcanic winter,
12:35an eruption might also strip away other parts of our atmosphere.
12:39A 2021 study published in Communications and Environment concluded that the Toba supervolcano
12:44eruption, which took place about 74,000 years ago, stripped a considerable amount of ozone
12:50out of the atmosphere.
12:51The culprit?
12:53Atmospheric gases like hydrogen chloride, which can disrupt the formation of ozone and
12:57provide a surface for ozone-busting reactions to take place.
13:01Atmospheric ozone is kind of a big deal.
13:03When it sits high in the stratosphere around our planet, it absorbs ultraviolet radiation
13:08from the sun, protecting our bodies from being blasted by cancer-causing rays.
13:13Chemical pollutants produced by humans can deplete ozone, too.
13:16Again, you really want an ozone layer.
13:19Without an ozone layer, UV radiation would sterilize the Earth.
13:23Thankfully, like the ozone damage caused by human pollution, volcanic ozone woes don't
13:28last forever.
13:29The ozone-depleting effects of an eruption are temporary, and often abate within just
13:34a few years.
13:35However, there's no telling how long ozone damage might last in the wake of an especially
13:39powerful supervolcano blast.