A Mind-blowing underwater volcano eruption amazes scientists !
Did you know that a huge and devastating volcano explosion occurred in early 2022?
Well, if you haven0t heard about it, this video is for you!
This eruption was the largest we have experienced in the 21st century! It was so powerful that
it produced shock waves that propagated across the entire world.
But what if I told you that this was not some rare occurrence? In fact, even more, devastating
eruptions have taken place before. For instance, in 2018, another underwater volcano erupted
off the coast of France’s Mayotte Island. But why does a volcano erupt so violently?
And what's exactly an underwater volcano? Let's find out!
Well, I bet you understand this video will be about volcanoes, especially underwater
volcanoes. In order to understand what an underwater
volcano is, it might be useful to talk about the differences between a “normal” one
and an underwater one.
Many volcanoes start out on land, rising above the surrounding landscape. But many more volcanoes
get their start at the bottom of the ocean. These underwater volcanoes, or submarine volcanoes,
can eventually grow into islands that rise above the surface of the ocean.
To date, geologists think there are more than 5,000 active underwater volcanoes.
If this is true, underwater volcanoes account for more than 75% of the total lava that erupts
every year. Most of these underwater volcanoes are located
along the mid-ocean ridges, where the Earth’s tectonic plates are spreading apart, and they
are very deep underwater. Therefore, most of the time they are difficult
to study, but in some lucky cases, they are located in more shallow water.
An underwater volcano erupts differently than a surface volcano. This is because there is
an unlimited amount of water to cool down the lava. What happens is that a shell of
rock hardens around the lava almost immediately, creating a type of formation called pillow
lava.
We know volcanoes build over time, and underwater volcanoes go through the same process, so
they build themselves in a similar fashion.
The height of an underwater volcano grows dramatically and eventually reaches the surface
of the ocean. This is, for example, what happened to form the Hawaiian islands. Isn't it amazing?
The Earth’s crust has drifted above an active vent, creating each of the islands in turn.
A new Hawaiian island, Lo’ihi, is forming under the ocean about 48 km off the southeast
coast of Hawaii. It’s already taller than Mount St. Helens and will breach the surface
in a few hundred thousand years.
As I said, the fact they are underwater makes submarine volcanoes difficult to study.
Only a few active sites have been studied in detail due to their inherent inaccessibility.
Scientists working on land can learn about the history of a volcano by visiting the volcano
site and gathering data. This can be done using cliff sequences or digging holes and
collecting materials. For underwater volcanoes, scientists usually
have to rely on marine surveys and mapping technology like sonar.
"It's like a really complicated layer cake," said Pyle, a volcanologist and professor of
earth science at the University of Oxford. "Somebody is going to cook this pretty complicated
cake and then bash it around and cut a hole in it, and if it's above water, you can just
go and have a look at it, and if they've dropped it in the bath then you're really stuck."
Well, now we know what an underwater volcano is. We're ready to talk about our news, the
powerful eruption that occurred in early 2022.
What really happened was that a volcano in the South Pacific decided to go nuts in January
2022 and shattered two records simultaneously: the volcanic plume reached greater heights
than any eruption ever captured in the satellite record, and the eruption generated an unparalleled
number of lightning strikes — almost 590,000 over the course of three days.
Atmospheric scientists said that this event was a hyper fuel for a mega thunderstorm because
the amount of superheated moisture from the ocean made this eruption unprecedented.
The plume went 2.5 times higher than any thunderstorm we have ever observed, and the eruption generated
an incredible amount of lightning.
This volcano has a name, we call it Hunga Tonga-Hunga Ha'apai.
It lies about 65 kilometres north of the Tongan capital of Nuku'alofa and sits within the
so-called Tonga-Kermadec volcanic arc, a line of mostly underwater volcanoes that runs along
the western edge of the Pacific Plate of Earth's crust.
For those of you who ask for the details, the eruption began on Jan. 13, launching explosions
that broke the water's surface and generating a major lightning event.
Then, on Jan. 15, rising magma from Hunga Tonga-Hunga Ha'apai met the seawater above
the volcano, triggering a sudden and massive blast.
Such explosive eruptions can occur when magma rapidly heats water into steam, which then
quickly expands; bubbles of volcanic gas caught within the magma also help to drive these
dramatic blasts up and out of the water, Nature reported.
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Underwater volcanic eruptions don't typically release large plumes of gas and particles
into the air, but the Jan. 15 eruption clearly was an exception to this rule. Not only people
could see the plume expanding in real-time: the best visual we have comes from satellites.
The first one, GOES-17, which stands for Geostationary Operational Environmental Satellite 17, and
the second one, Himawari 8 from Japan Aerospace Exploration Agency, captured the unusual eruption
from above, allowing scientists at NASA's Langley Research Center to calculate how far
the plume penetrated the atmosphere. Having two satellites looking at the plume
from different positions is not something that happens every day, especially when it
comes to underwater volcano eruptions. Having two satellites means being able to
recreate a three-dimensional picture of the clouds. This is exactly what scientists from
the NASA Langley team did. Clouds' determination suggested that, at its
highest point, the plume was 58 km high in the air. This tells us something amazing:
the plume literally pierced the mesosphere! The mesosphere is the third layer of the atmosphere,
directly above the stratosphere and directly below the thermosphere. The exact upper and
lower boundaries of the mesosphere vary with latitude and with the season (higher in winter
and in the tropics, lower in summer and at the poles), but the lower boundary is usually
located at altitudes from 50 to 65 km.
After an initial blast generated this towering plume, a secondary blast from the volcano
sent ash, gas and steam more than 50 km into the air.
However, the one from Hunga Tonga is not an isolated volcano eruption event.
For example, back in 1991, Mount Pinatubo in the Philippines unleashed a plume that
extended 35 km above the volcano, and until the recent Hunga Tonga-Hunga Ha'apai eruption,
that 1991 event held the record for the largest known volcanic plume in the satellite record,
the statement noted.
Coming back to our January 2022 eruption, what happened to the plume when it reached
the mesosphere was a quick transition into a gaseous state.
But in the stratosphere below, gas and ash from the volcano accumulated and spread to
cover an area of 157,000 square kilometres.
This eruption seems to have created some sort of waves in the atmosphere. Such waves can
influence the pattern of lighting strikes. That's why eruptions are so important to meteorologists.
To study the lightning, the team is using data from GLD360, a ground-based lightning
detection network. These data revealed that, of the nearly 590,000 lightning strikes that
took place during the eruption, about 400,000 occurred within six hours after the big blast
on Jan. 15. The contribution from the underwater volcano is therefore incredible! We are talking
of 67% of lighting strikes due to Tonga! Well, we've seen this eruption was really
something out of this world! But do we know something about other eruptions
that happened over the course of history and maybe pre-history? Well, although there’s
no way to map every possible volcanic event ever—especially when we’re talking millions
and millions of years—one big blast throughout history will always make its way into the
room: Yellowstone National Park, some 640,000 years ago.
The Supervolcano’s eruption shaped the national park, holding rank in scientific studies as
the stuff of legend. Yellowstone’s geysers and seismic activity are a constant reminder
of what lurks beneath, and that it can be dangerous!
Another big eruption that we know about is the one of mt. Tambora—which is still active
today. It was the most explosive volcanic event ever
recorded by humans. The initial blasts back in April 1815 were heard some 1900 km away.
To put that into perspective, imagine hearing an explosion in Tampa Bay, Florida… that
occurred in New York City, and then add another 321 km on top of that! It's mind-blowing,
isn't it? Coming back to our Tonga eruption, we want
to talk about something sad. The Tonga eruption happened just 65 kilometres
from the Tongan capital of Nuku‘alofa. This has been a disaster for the more than
100,000 people living in the surroundings.
They lost clean-drinking water supplies and they are currently working to clear away the
thick layer of ash that blanketed everything. At least three people have died in Tonga as
a result of the eruption. In this gif, you can appreciate an areal view
of the city before and after the eruption.
The thing is... earthquakes and eruptions will always continue to shake the region,
and the volcanic danger will never really be over. Hunga Tonga–Hunga Ha‘apai could
remain active for some time, with uncertain effects on the people living there.
Regardless of what the immediate future holds for this particular volcano, the eruption
has volcanologists rethinking the hazards of submarine volcanoes more broadly.
It’s a stark reminder that these kinds of volcanoes exist and that they pose a hazard.
Maybe a more detailed study could help us to better face this huge problem.
As you can understand, the power of the Earth and nature is something that we can't completely
control. But, with the help of science, we can lower the risks and better appreciate
the beauty of the world we're living in.
"This video ends here! Thanks for watching everyone! Are you scared of volcanic eruptions?
Do you have a favourite volcano? Let us know in the comments below, be sure to subscribe,
and I'll see you next time on the channel!"