One of the largest volcanic eruptions in recorded history occurred to the east of Australia
in 1452.
Overnight, a large portion of an island sunk into the ocean, causing several thousand feet
in height to just vanish.
This eruption was so large that it split the overall island in two, forming a massive 12
kilometer wide caldera which is now filled by the Pacific Ocean.
The volcano I am referring to is called Kuwae, which is located in the nation of Vanuatu.
This video will discuss this volcano, its massive eruption in 1452, and discuss what
hazards it poses in the future.
The Kuwae volcano is located in the Pacific Island nation of Vanuatu.
Specifically, it is located 100 kilometers north of the nation's capital, Port Vila.
Before the caldera collapse in 1452, the Kuwae volcano did not exist, as instead there were
at least two separate volcanoes sitting atop a 5.5 kilometer wide isthmus of land.
This stretch of land contained numerous smaller volcanic features such as lava domes, and
was covered in rainforest.
These two volcanoes each originally started below sea level beginning approximately 400,000
years ago.
However, they started in a shallow portion of the Pacific Ocean due to other regional
volcanoes, and began erupting at a depth of only 300 meters.
Over the subsequent tens of thousands of years, layers of basalt piled on top of one another
to form two distant basalt stratovolcanoes.
Eventually, these volcanoes reached the ocean surface, thus explosively erupting and forming
new islands.
As the volcano to the northwest continued to grow in size, it erupted in a more variable
manner, producing both layers of andesite and basalt.
My interpretation of these layers are that alternating strombolian style eruptions alongside
more explosive vulcanian eruptions deposited on top of one another, much like seen today
at the nearby Yasur volcano.
The second volcano to the south exclusively erupted in a strombolian and effusive manner,
ejecting bombs of lava in a several kilometer radius along with intermittent tall lava fountains.
Through hundreds of eruptions, this volcano grew in size to 5.5 kilometers wide and 900
meters tall.
It likely had a strong red color on its summit and eventually this volcano connected to the
northwestern volcano, forming a single island.
However, something at depth began to change.
The same magma chamber which fed the two distant volcanoes began to leach additional silica
from surrounding rock into the liquid magma.
This caused the compositon of the magma to change, resulting in a series of unusually
explosive lava dome forming eruptions which ejected a different rock type called dacite.
Then, several thousand years ago, a prolonged period of dormancy began.
Underneath the island, the magma chamber slowly grew in size and pressure.
Then, late in 1452, a new batch of magma rose towards the existing magma chamber, thus causing
the two to mix.
This caused a chain reaction, resulting in an immense amount of magma shooting up towards
the surface.
Then, a group of several vents simultaneously erupted in the middle of the island, creating
a towering plume of ash.
While this was occurring, immense quantities of volcanic gasses escaped onto the surface,
resulting in the creation of pyroclastic flows.
These pyroclastic flows raced across the island and into the Pacific Ocean, traveling up to
80 kilometers away before they stopped.
Due to the immense amount of magma which erupted, a wide swath of the existing island collapsed
downwards by 950 meters to fill the nearly empty magma chamber.
This collapse occurred much like a sinkhole, resulting in a massive caldera.
What had just occurred was one of the largest eruptions of the last 10,000 years, rating
on the volcanic explosivity index as a 7.
In total, 101 cubic kilometers of ash was ejected.
Since this caldera collapse, a single volcanic cone has rebuilt itself from the ocean floor,
called Karua.
An eruption from 1897 to 1901 constructed a 1 kilometer wide island, which washed away
in 6 months.
Again, in 1949 the volcano erupted, building a slightly larger island which washed away
within a year.
The last time this volcano erupted was in 1974.
However, given the frequency of eruptions from this volcanic cone, it will erupt again.
On average, an eruption from Kuwae occurs about once every 12 years.
Luckily, these eruptions tend to be isolated and small in size, so future eruptions will
build additional islands until the volcano permanently climbs above the ocean's surface.
I hope that you enjoyed this video!
If you would like to request a specific topic, please leave a comment below!
Additionally, if you wish to support this channel, consider becoming a patron on patreon.