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Find out more interesting things about volcanoes in this video!
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00:01Wow! Earth's surface is shaking. Long cracks split the ground open. Lava rivers are rapidly flowing down the slopes. Deafening
00:09noise is filling the air. Rocks and other debris are flying high up. Clouds of volcanic gas and ash cover
00:16the sky.
00:17Now, this is not a plot of a blockbuster disaster movie. It's what happens when supervolcanoes decide to erupt. But
00:24this is likely not the scenario that will take place when the world's largest volcano, Mauna Loa, decides to finish
00:31its long, long nap.
00:33In 2021, scientists were sure it would happen soon. But so far, nothing. The volcano's seismicity keeps increasing and then
00:42going back to normal. But you never know when this giant will finally come back to life.
00:48That's why experts have been monitoring geological activity on Hawaii's largest island for quite some time.
00:54The big island of Hawaii is made up of five volcanoes, including the most active on the planet, Kilauea, and
01:02the largest, Mauna Loa.
01:03This gigantic thing makes up almost half the landmass of the island. And what Lava Kilauea emits in one day,
01:11Mauna Loa could spew out within 20 minutes. That's what it did in 1984.
01:16While Mauna Loa's smaller sibling has been throwing tantrums for a while, the giant has been slumbering ever since its
01:24last eruption.
01:25But very recently, the Hawaii Volcano Observatory has recorded more than 200 mini-earthquakes below Mauna Loa. It likely means
01:34an increased flow of magma down there.
01:40If Mauna Loa did suddenly erupt, lava flows could reach the ocean and the most populated and touristy places, like
01:48Captain Cook, very, very quickly, in a matter of hours.
01:51In 1984, the last time the volcano erupted, lava got as far as the outskirts of Hilo on the other
01:59side of the island.
01:59That's where a campus of the University of Hawaii is found. Luckily, people had a few weeks' warning to get
02:06ready for the disaster.
02:07These days, locals have special go-bags ready with the most important stuff, including documents and money.
02:14Such precautions can come in handy in case of an emergency evacuation.
02:19Even though most Mauna Loa eruptions have so far only affected the summit area, several of them sent lava all
02:26the way down to the ocean.
02:27And you never know how powerful the next eruption will be.
02:31Now, what is the highest mountain on Earth? Mount Everest, you say?
02:35Well, it depends.
02:37From seafloor to the summit, Mauna Loa is a thousand feet taller than the famous Himalayan Peak.
02:43The volcano is so big, it makes the Pacific plate it's sitting on literally slump under its weight.
02:49Scientists say that when this monster of a volcano erupts, the volume of lava coming out per unit will be
02:56life-threatening.
02:57Over its recorded history, Mauna Loa has been erupting regularly, almost every six years.
03:03And even though the last eruption of the volcano occurred about 40 years ago, scientists are certain it'll happen again.
03:11Now, remember the scene I showed you at the beginning?
03:14Well, you can relax. It's not likely to happen with Mauna Loa.
03:18The thing is, big island volcanoes, including Mauna Loa, aren't very volatile.
03:23That's because they're shield volcanoes.
03:26These volcanoes got such a name because they aren't really very high and resemble a warrior's shield placed flat on
03:33the ground.
03:33Shield volcanoes get formed by very fluid lava.
03:37It travels farther and forms much thinner flows.
03:40Then lava erupted from a stratovolcano, which is conically shaped and tall, like the infamous Krakatoa in Indonesia.
03:47So if, or should I say when, Mauna Loa erupts, there probably won't be ash clouds and tons of debris.
03:55The most dangerous thing will be lava.
03:58Since Mauna Loa is a shield volcano, its lava is extremely fluid and voluminous, which allows it to flow far
04:04and fast.
04:06Using theoretical vent maps, experts from the Hawaii Volcano Observatory have made charts of possible lava flows.
04:14They're kind of worried about earthquakes clustering at high rates.
04:18It likely means that lava is on the move under the surface.
04:22500 to 600 earthquakes per day are a serious reason to be on high alert.
04:27On the other hand, it doesn't necessarily mean a disaster or inevitable eruption.
04:33Around a decade ago, several earthquakes that happened at the same time signaled that something was happening under Mauna Loa.
04:41But an eruption didn't occur.
04:43Instead, half the volcano shifted a bit to the south.
04:47This way, it probably gave more room to magma so that it had enough space to stay beneath the surface.
04:53Now, let's get back to the catastrophic eruption we saw at the beginning of the video.
04:58That's what often happens when a supervolcano erupts.
05:01Those are volcanoes that have at least once had an eruption with a volcanic explosivity index of 8, which is
05:08the largest recorded number on the index.
05:11Supervolcanoes are often extremely large, with no cone at all.
05:15That's because they're typically the remains of gigantic magma chambers that once flared up, leaving behind a caldera.
05:23They're usually found over hot spots.
05:25Supervolcanoes can produce supereruptions.
05:28And when they do, they blow more than 240 cubic miles of ash, molten rock, and hot gases up into
05:35the air.
05:36In other words, four supereruptions could fill the Grand Canyon to the brim.
05:42Supervolcanoes get formed when gigantic volumes of scorching hot magma are trying to escape from deep underground.
05:48This magma rises close to the surface, but can't break through Earth's crust.
05:53That's why a huge pressurized pool of bubbling magma gathers at a depth of only several miles.
06:00The pressure keeps growing because more magma is trying to get to the surface.
06:04Until, bam, a supereruption occurs.
06:08The most recent supereruption happened in New Zealand.
06:11Well, when I say recent, I mean around 26,500 years ago.
06:16Nah, I wasn't around then.
06:18That's when a supervolcano beneath the surface of Lake Taubo spewed into the air more than 300 cubic miles of
06:25ash and pumice.
06:26Imagine 500,000 Great Pyramids of Giza flying up at the same time.
06:31That's how incredibly powerful that eruption was.
06:35But the most exciting and confusing thing about the eruption was that the Taubo volcano simply didn't go off like
06:42many others.
06:43At first, everything was going as usual.
06:46More than 200 square miles of magma had built up under the surface, and the pressure was getting higher and
06:52higher.
06:52But after the rock cracked and the first part of lava rushed out of the crater, something went wrong.
06:58And the supervolcano took a break.
07:00Only several months later, the disastrous eruption shook the ground, and thousands of tons of lava, rocks, and ash flew
07:09high into the atmosphere.
07:11But the age of supervolcanoes isn't over.
07:14The most infamous of them all is probably the one in Yellowstone National Park.
07:19This giant handles at least three mega-powerful eruptions, and who knows how many smaller ones.
07:25If this monster erupted anywhere as strongly as it did 2.1 million years ago, it would spit out more
07:32than 588 cubic miles of red-hot material.
07:36You can probably picture it more vividly if I tell you that this volume is comparable to 65 million capital
07:43rotundas in Washington, D.C. piled together.
07:46Wow.
07:46Anyway, scientists are sure that Yellowstone doesn't present any danger these days.
07:52For an eruption to happen, magma inside must be at least 50% molten.
07:57With the Yellowstone caldera, this number is just 5 to 15%.
08:01But of course, Yellowstone isn't the only supervolcano on our planet.
08:06There's also New Zealand's Taubo you already know about, Japan's Eri Cauldre, California's Long Valley, Indonesia's Toba, any of them
08:15can one day produce a supereruption.
08:18There are also several so-called supervolcanoes that haven't lived up to this name yet, because they've never produced anything
08:26like a supereruption.
08:27For example, in 1883, Indonesian volcano Krakatoa went off.
08:33The power of the eruption tore the volcano's walls open, and cold seawater rushed into its molten insides.
08:40The difference in temperature made the volcano blow up with a deafening boom.
08:45It was clearly heard 2,000 miles away in Australia.
08:49It earned the blast the title of the loudest sound in history.
08:53But even though the consequences of this event were truly catastrophic,
08:57it still turned out not powerful enough to be called a supereruption.
09:02One of the few places you haven't traveled to yet is a volcano.
09:07It's an opening in the Earth's crust, through which hot gases, molten rock, and other stuff get to the surface
09:13of the planet.
09:14But which one should you choose?
09:15There are different kinds of them.
09:17For example, shield volcanoes are built almost entirely of solidified lava flows,
09:22or lava domes formed by small masses of lava that are too thick to travel great distances.
09:28You can also pick a cinder cone.
09:31It's the simplest kind of volcano out there.
09:33It's built from blobs of almost solid lava that erupts from a single vent.
09:38This lava is ejected into the air with great force.
09:41Then it breaks into tiny fragments that become solid and fall back as cinders.
09:46With time, they form an oval or circular cone around the vent.
09:51Such cones rarely rise more than 1,000 feet.
09:54But what if you choose something even more impressive?
09:57How about traveling down a stratovolcano?
10:01Huge, steep-sided, and powerful.
10:03Once you've made your choice, you also decide to opt for an active volcano that is erupting at this very
10:10moment.
10:10What you're observing now is called a glowing avalanche.
10:15The volcano has just erupted a huge portion of lava, which has created a pyroclastic flow.
10:20Its temperature can reach an insane 1,300 degrees Fahrenheit.
10:25You see how this flow gets formed from rock fragments and surges down the flank of the volcano at a
10:31speed of several hundred miles per hour.
10:33Ash is raining down on Earth like grayish, powdery snow.
10:37Volcanic ash consists of tiny particles of pulverized rock, volcanic glass, and minerals.
10:43When the ash gets mixed with the water from mountain streams and rivers, raging mud flows appear.
10:49Despite how scary it all looks, you get closer.
10:52Good thing you're wearing a protective suit that can withstand any temperature.
10:56The nearer you get, the more fumaroles you spot.
11:00These are holes and cracks at the base of the volcano and in its slopes.
11:05They emit huge clouds of steam and volcanic gases, carbon dioxide and sulfur dioxide.
11:12Some of the cracks are so large, you can probably squeeze through and sneak a peek inside the volcano.
11:17But you have a different destination, the crater.
11:21On your way there, you spot a strange conical structure on the side of the volcano.
11:26It looks like a horn growing on the main cone.
11:29It must be a secondary cone, also known as a parasitic cone.
11:34Such cones form around secondary vents that reach the surface of large volcanoes.
11:38In this case, an eruption can occur not only through the main vent at the top of the volcano, but
11:44also through these additional vents.
11:47In any case, that's not where you're heading.
11:50Soon, you reach the crater.
11:52It's a massive circular basin.
11:54When you go to its edge and look inside, you see it's also very deep.
11:59The lava vent, which is where you need to go, is at the bottom of the crater.
12:03But even before jumping into the vent, you spot some strange tubes hiding under the lava flow.
12:09Those are lava tubes.
12:11Natural passages through which fresh liquid lava travels beneath the surface of the lava flow.
12:16You decide to make a detour and follow one of the tunnels.
12:20It's the main lava tube.
12:22You also spot several smaller tubes.
12:24They supply lava to one or more lava flows.
12:27If the volcano wasn't erupting at the moment, the lava would drain downslope from this tube system.
12:33The passages would have lava marks on the walls, a flat floor, and lava stalactites hanging from the ceiling.
12:39But even now, there's some empty space above the flowing lava.
12:43That's because it has eroded downward, making the tube deeper.
12:47But right now, you need to get back.
12:50You take the next turn and get back to the crater.
12:53You wait till the volcano spews another portion of boiling lava and dive into the volcano's throat.
12:59It's the entrance of the volcano.
13:01Now, lava and volcanic ash get ejected from here.
13:04The volcano's throat is wide, and you easily travel deeper down.
13:09The lava around you glows bright red and orange.
13:12That's because when it first bursts to the surface, its temperature can reach 2200 degrees Fahrenheit.
13:18That's hot enough to melt iron.
13:20You move down the volcano's main vent.
13:23It's a weak point in our planet's crust.
13:25There, scorching hot magma manages to escape from its chamber and reach the surface.
13:30While going deeper and deeper into the vent, you notice sills.
13:35Sometimes, lava intrudes between the crack in the crust, pools there, and crystallizes.
13:41This creates deposits of ash and solidified lava.
13:44That's what sills are.
13:45Pretty soon, you reach a magma chamber.
13:49It's a large pool of molten rock.
13:51The one you're in at the moment is quite shallow.
13:54That's because it's not the main one.
13:56After traveling several more miles down through the vent, you get to another huge magma chamber.
14:02It supplies the small one beneath the base of the volcano.
14:06The main magma chamber lies in Earth's crust, which stretches from 3 to 44 miles deep.
14:13The molten rock there remains under extreme pressure, and the temperatures inside are incredibly high.
14:19With time, the rock surrounding the magma chamber starts to break and fracture.
14:24This creates outlets for the magma.
14:26And since it's made of a much less dense material than the surrounding rock,
14:30the magma begins to seep through the cracks to the surface.
14:33From the main chamber, it rises to the upper one.
14:37Then it makes its way to the surface in a powerful eruption.
14:40You explore the magma chamber and then decide to go even deeper than that,
14:45to the place from where all that molten rock gets into the magma chamber.
14:49You're moving through the crust.
14:51The volcano is located on land.
14:53That's why your trip takes longer than it would if you were traveling through the oceanic crust.
14:58It's only 3 to 6 miles wide.
15:00But the continental crust is much thicker.
15:03It can be 28 miles thick in some places.
15:06As you're going through the crust, you can't but notice its light color.
15:10That's because it consists mostly of granite.
15:13If you were going through the oceanic crust, the material surrounding you would be dark or nearly black
15:19because it has a different composition.
15:22The deeper you go, the hotter it becomes.
15:24Sure, the temperature here isn't as high as in the magma chamber.
15:28But still, at the boundary with the mantle, your thermometer shows 750 degrees Fahrenheit.
15:34At a depth of about 20 miles, you reach the boundary between the crust and the Earth's upper mantle.
15:40There, the pressure reaches a mind-boggling 10,000 atmospheres.
15:45That's where magma comes from.
15:47You could finish your journey and get back to the surface, but your curiosity gets the better of you.
15:53You decide to go deeper, all the way to the center of the Earth.
15:57The next layer on your way is the mantle.
15:59It makes up two-thirds of the Earth's mass and 84% of our planet's volume.
16:05It's 1,800 miles thick.
16:07The rock closer to the inner part of the mantle is semi-solid, like caramel candy.
16:12The upper part of the mantle, as well as the crust, is broken into massive pieces.
16:17They look like a colossal jigsaw puzzle.
16:19Those are tectonic plates.
16:21They drift at a speed of 1 to 2 inches per year.
16:25You're moving through the upper mantle and feel the temperatures rising up to 1,600 degrees Fahrenheit.
16:31Near the boundary with the core, the temperature is already as high as 7,000 degrees Fahrenheit.
16:37The pressure in the lower mantle reaches 240,000 atmospheres.
16:42You'd feel the same pressure if 3,300 elephants made a tower on your head.
16:47At a depth of about 1,800 miles, you see the boundary between the mantle and the outer core.
16:53The insides of the planet around you are heated up to 9,000 degrees Fahrenheit.
16:57Such temperature is high enough to keep the outer core liquid.
17:01The pressure there is almost 2 million atmospheres.
17:05But it's not enough to make the iron that the core is made of solid again.
17:09The outer core is 1,500 miles thick.
17:12It churns in massive turbulent currents and generates a magnetic field.
17:17In the outer core, Earth's magnetic field is 50 times more powerful than at the surface.
17:22You are now more than 3,000 miles underground, and you've reached the inner core.
17:27It's a solid metal sphere around 1,500 miles across.
17:32The inner core is immensely dense and spins faster than the rest of the planet.
17:37The temperature there is as high as on the surface of the sun, 9,800 degrees Fahrenheit.
17:42And the pressure inside the inner core is 3 million times greater than on the surface.
17:47It took about 500 million years for the inner core to form, which means it's younger than some parts of
17:53the crust.
17:56Day 1.
17:57A small but powerful tremor is shaking the city of Naples, Italy.
18:02The news networks are reporting on the event.
18:04The experts believe that Mount Vesuvius, the stratovolcano on the Gulf of Naples, will explode soon.
18:11But when?
18:12It's erupted many times in the past.
18:14In fact, that's how it got its shape.
18:16It's made of multiple layers of hardened lava, pumice, and ash.
18:21Vesuvius last erupted in 1944, but a major blast happened there nearly 2,000 years ago.
18:28It buried the Roman towns of Pompeii and Herculaneum and decimated the surrounding areas.
18:34Today, 3 million people live less than 20 miles from the volcano, and 600,000 live in the danger zone.
18:41Large eruptions happen every few thousand years, usually after long periods of calm.
18:47And the trouble is, Vesuvius is long overdue for its next one.
18:52Right now, the magma is more than 6 miles from the surface.
18:56Things seemed safe yesterday, but now they're about to take a turn for the worse.
19:02Day 3.
19:03Another tremor comes in measuring 3 on the Richter scale.
19:07All the equipment that's installed near the volcano is now going off.
19:11The magma is pushing upwards.
19:13It's not at the surface yet, but Vesuvius is definitely restless.
19:18Two more tremors follow in the afternoon.
19:20They don't feel like regular earthquakes, and geologists can see the difference in their seismographs.
19:26Volcanic quakes register about 4 to 5 less on the Richter scale.
19:31Now, the experts are sure.
19:32It's just a matter of days or weeks until the volcano erupts.
19:37Some volcanoes can be restless for months or even years before they go off.
19:41But that's not how it goes with Vesuvius.
19:45Day 4.
19:46The ground starts to crack open, as if a giant creature is trapped in the Earth's crust
19:51and is trying to desperately get out for some air.
19:54Steam escapes from the little cracks in the soil.
19:57Certain areas are hotter than others.
19:59If you went there, it would feel like you walked straight into an oven, and it would be hard to
20:04breathe.
20:04Some sheep got too close to the mountain and passed out.
20:08When the farmer found them, he almost collapsed too.
20:11Not from the heat, but from the gases.
20:13Carbon dioxide and hydrogen sulfide are being released into the air.
20:17The entire area around the volcano smells like rotten eggs, and many of the forest animals are now staying clear.
20:25The nearby trees have been absorbing these gases from the soil for days on end now, and they're starting to
20:31turn brown.
20:32The carbon dioxide levels in the area are skyrocketing, and all the detectors are beeping constantly.
20:38Day 6.
20:41The tremors are getting more frequent.
20:43Experts at the Vesuvius Observatory monitoring the volcano say the quakes are coming from the magma that's being pushed upwards.
20:50A few hours later, the national emergency alert goes out.
20:54Thousands of local people have around 15 days before the volcano erupts, and they need to evacuate their homes.
21:00The 600,000 people in the danger zone start to pack their suitcases and leave in cars and trucks.
21:07There's chaos everywhere.
21:09But in all that disorder, some people are standing still.
21:12They look around, trying to understand what's really going on.
21:16A few of them are taking photos of their homes.
21:19Others are streaming all the confusion on social media.
21:22But the senior citizens are just standing outside, looking at their houses one last time.
21:28They hope this is all just a false alarm.
21:31It's happened before, but who really knows?
21:36Day 7.
21:37It was a sleepless night.
21:39Plenty of the locals have already left.
21:41Some good people from other towns drive to the area to help the residents evacuate faster.
21:46There's a massive traffic jam, but everyone expected it.
21:50This is why the evacuation started early.
21:53Ferries, trains, and buses have canceled their services to help the evacuees.
21:57They're all working on a tight schedule to make sure everyone gets out safe without any delays.
22:03Some people refuse to leave, but their neighbors eventually convince them to go.
22:07It will take seven days to evacuate everyone, and these people will spread out to other areas of the country,
22:14not just to the nearby safe regions.
22:17Day 10.
22:18More than half of the residents have now left the red zone.
22:22After the chaos, there's now silence, and it's interrupted by the eerie sounds of the tremors.
22:28Animals are being evacuated, too.
22:30Many people are now trying to save as many animals from the forest as they can find.
22:36Day 16.
22:38All 25 of the towns that were at risk have now been evacuated.
22:42The red zone is empty.
22:44But the tremors are getting stronger, as the volcano is a pressure cooker ready to explode.
22:50White smoke rises from the large opening on the mountaintop and the vents on the side.
22:56The molten rock moves toward the surface, and the pressurized gases form bubbles, just like the ones you see when
23:03you boil food.
23:04Suddenly, there are some loud booms, and then an explosion.
23:09It's loud enough to be heard thousands of miles away, and the shockwave is felt throughout Italy.
23:14Volcanic rock is thrown up into the air.
23:17A thick black mushroom cloud forms and expands into the sky.
23:22The birds abandon their nests and fly away in huge flocks.
23:25The red-hot lava is now spewing out of the volcano like a fountain.
23:30As it flows downward, it obliterates everything in its path.
23:33Then, there's a volcanic landslide.
23:36Part of the cone-shaped mountain falls off, and millions of tons of soil and rock break loose from the
23:42volcano's side and tumble down.
23:45The lava spreads on the slopes, and it slowly slides down into the forest and the farmlands.
23:51The plume of ash, pumice, and other kinds of rock has risen so high into the sky that people can
23:57see it from Rome.
23:58Then the tower of debris starts falling back to Earth.
24:01First comes the ash, then chunks of rock.
24:04The ash in the atmosphere is so dense that it's hard to breathe.
24:08The lava slowly spreads across the area and pulls down all the trees.
24:13All the nearby towns are shrouded in darkness and smoke.
24:17Buildings collapse, and all around there's a mixture of heated, poisonous gas and rock moving faster than a car.
24:23Other rocks and more volcanic ash fall miles away from the volcano, hitting cars and destroying roofs.
24:30The sky is completely black as the lava keeps on coming.
24:34Slowly, all the nearby towns are submerged beneath the molten rock.
24:39Some of the lava even reaches the sea.
24:42Gigantic white steam covers the shore where it falls in, and the magma turns black.
24:47Now, a weird neon blue fire appears on the slopes of Vesuvius.
24:52This is caused by burning sulfuric gases.
24:55They're escaping at high pressure from the cracks in the volcano's surface.
24:59When they come into contact with the air, they ignite.
25:02These blue flames can reach 16 feet into the air.
25:06Now, all nearby flights are canceled, and many planes have to change course to reach their destination.
25:11Ever since the national alert, no planes have been allowed to fly over the volcano.
25:17The clouds of volcanic ash can damage jet engines and other plane components.
25:21The water supply is now contaminated by streams of volcanic ash, and it smells unbelievably bad.
25:28In just a short amount of time, all that magma has made entire towns vanish.
25:34Only the roofs of taller buildings can be seen.
25:37After the big and explosive eruption, there are some smaller and quieter ones.
25:41At this stage, nobody knows if the volcano has stopped erupting yet,
25:46and absolutely no one can go anywhere near the area.
25:52Ten years later.
25:53Most parts of the Red Zone are now hidden under hardened but still warm lava,
25:59including the ancient site of Pompeii.
26:01Some people have started to forget about what happened.
26:04Others have begun their new lives elsewhere,
26:07and some don't even want to think about what happened to their old homes.
26:11But several of them are counting the days until they can go back.
26:16One hundred years later.
26:18You're walking in what appears to be a wasteland of volcanic ash.
26:22You suddenly realize that you're standing on top of your great-grandparents' town.
26:28Everything is now submerged under a thick carpet of solidified lava.
26:32But below it all, just about everything is still intact, completely frozen in time.
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