How do you imagine the world's most powerful
volcano eruption? Boiling-hot orange lava spilling over the
slopes of a mountain and destroying everything in its path? Ginormous clouds of ash, blacking out the
sky and wiping out all the life in nearby towns? Toxic gases that sneak into the smallest nooks?... (Hmm, I give up.) But what if I tell you that you might not
even notice this devastating event? Few people know that around 80% of all volcanic
eruptions happen underwater. What's more, submarine volcanoes alone spit
out more than 75% of the world's magma. There are over 1 million underwater volcanoes
on our planet, and at least 75,000 of them rise above the seabed by more than half a
mile. But as you may guess, it's very hard to explore
and examine these underwater monsters. No wonder scientists almost missed the largest
underwater volcano eruption of our time! A Kiwi passenger was flying back home after
having an amazing vacation in Samoa, when something strange attracted her attention. At that moment, the plane was several hundred
miles away from the coast of New Zealand, and from her window seat, the traveler saw
a bizarre large mass, floating on the ocean’s surface. She took a photo, and after returning home,
she sent this picture to researchers. It turned out that the mass was a huge raft
of pumice rocks, some of them as big as a car. This moving carpet, which spread for a whopping
150 square miles, was the result of the greatest submarine eruption in modern history! Even more, several months later, satellites
spotted that the pumice rock raft had already spread over an area the size of two New Zealands! Havre Seamount volcano, which exploded on
July 18, 2012, lies between American Samoa and New Zealand in the southwest Pacific Ocean. Three years after the eruption had happened,
scientists packed into two autonomous underwater submarines and headed to explore the area. At that time, they already knew that there’d
been a massive explosion, comparable to the largest land eruptions of the 20th century. In any case, researchers expected to discover
some evidence of a common deep-sea eruption. But they were in for a surprise. To their endless amazement, scientists didn't
find a typical underwater volcano blast pattern. But what they discovered was so much more
unexpected! The seafloor, miles away from the volcano,
was littered with giant pumice blocks, and some of them were the size of a van! Scientists admitted later that they’d never
seen anything like that before. At first, those who were inside the submarines
even thought that something was wrong with their imaging systems. Now, let me go a bit off-topic. (Like I never do that..ha.) The thing is that underwater volcanoes are
usually gentle giants that don't bother us too much. When they erupt, it can easily go unnoticed,
due to their distant location. All the fun happens deep underwater. When the time comes, the pressure blasts the
whole top of the volcano off, and magma gets thrown high up with an incredible force. The amount of red-hot magma is so huge that
it boils millions of gallons of water in a matter of minutes. As a result, the region around the erupting
volcano turns into a rolling cauldron of water, which then floats up to the surface. If you were somewhere around at that moment,
you would see the ocean start to bubble furiously, and you’d smell the disgusting stench of
sulfur. Whew! The deadly cloud of boiling water would destroy
all the plants and marine animals caught near the eruption, and later, these remains would
rise to the surface to add to the mystery of the bubbles and smell. But it turned out that the Havre volcano eruption
was an unusual one. The caldera (which is a large crater that
appears after massive eruptions) spanned for almost 3 miles, and 14 vents in it spewed
out huge amounts of lava. But the most interesting thing was that the
volcano produced not only pumice rocks, but also lava domes, ash, and even underwater
lava flows! Remember the 2010 Eyjafjallajökull eruption
in Iceland which caused unprecedented problems with air travel that lasted for 6 days? (Wait wait wait -- hold on. [put word on screen as in a spelling lesson]
Say it with me now: Eyjafjallajökull. …well, work on it -- there’s your homework
assignment.) Anyway, the Havre underwater eruption was
10 times more powerful than that. Scientists were ecstatic about this finding. They stated that the samples they’d found
equaled a decade of thorough research. Thanks to these materials, researchers have
a unique opportunity to understand better what happens when an underwater volcano flares
up. But nowadays, we have a more burning issue
on our hands. It seems that climate changes may affect not
only weather and sea level, but also trigger disastrous volcanic eruptions all over the
planet, both underwater and on land! The thing is that glaciers might be suppressing
volcanic activity by making mountains more stable. But these days, as the ice starts to melt,
mountains don't have the support they had before. For a usual mountain, it might mean landslides,
and probably even collapse, but if we’re talking about a volcano, the situation turns
much more dangerous. You might already know that volcanoes experience
constant pressure from the inside. So, remove at least one outer protective layer
(and by saying that, I mean the snow or ice cover) - and you have a huge powder drum that
could explode at any moment. But what if all the volcanoes on Earth lost
their stability and went off simultaneously? Oh, that would be an apocalyptic scenario. (You kinda knew I was going there, didn’t
you?) You can probably imagine the panic every single
person on the planet would feel should all the volcanoes erupt at once. Some volcanoes would only ooze liquid lava
all over their own slopes and the nearby settlements. Luckily, in this case, the inhabitants would
have enough time to evacuate and get away from dangerous zones. As for conical stratovolcanoes, like Mount
Fuji in Japan, for example, they would cause much more trouble. Such volcanoes would produce so much ash that
it would darken the sky for weeks and months. It would trigger a long and freezing volcanic
winter. Without sunlight, plants and crops would die,
unable to get energy from photosynthesis. Animals, as well as people, would suffer from
food shortages. An even more dangerous problem would be the
ash itself. Once inhaled, volcanic ash turns into a glass-like
substance inside people's lungs, and you can probably guess the tragic outcome. People hiding inside buildings would be in
grave danger, because under the combined weight of ash, construction would start to collapse. Since ash is 5 times denser than water, most
buildings are simply not designed to withstand tons of it on their roofs. Besides, when stratovolcanoes began to erupt,
they’d send huge lava explosions into the air, and lava would also flow down the slopes
at unprecedented speeds. In this case, you wouldn't be able to escape
by hopping on a plane, because the aircraft's engines would stop as soon as the ash re-melted
into drops of lava inside them. But even those wouldn't be the worst consequences
of all the volcanoes erupting at once. (No no, let’s just pile on here.) By the end of the eruptions, the world would
be encompassed by a volcanic winter, and the very concept of seasons would become outdated. Huge unstable carbon reservoirs in the oceans
would become liquid and would be turned into methane and carbon dioxide by microbes. These two greenhouse gases would get into
the atmosphere and dramatically accelerate global warming. It would create a never-ending vicious circle:
a warmer climate would cause more gases to enter the atmosphere, which would, in turn,
warm the climate even more. Eventually, the climate would get so incredibly
hot that all the trees and plants would die out, all the oceans would boil away, and Earth
would turn into a Venus-like place - a planet with no liquid water and the atmosphere filled
with deadly carbon dioxide. Are you thoroughly depressed yet? Well enough of this gloom and doom -- We’re
on the Bright Side after all – and you can relax now: luckily, this scenario is highly
unlikely to ever occur, and we can just sort of theorize about the “what ifs...” How about you? Have you ever seen a volcano, active or sleeping? Can you say: Eyjafjallajökull? Do you know how hard I practiced to say that
right? Let me know down in the comments! If you learned something new today, then give
this video a like and share it with a friend. But – hey! – don't go to, you know, that
volcano-- just yet! We have over 2,000 cool videos for you to
check out. All you have to do is pick the left or right
video, click on it, and enjoy! Stay on the Bright Side of life!
