Despite India containing a section of the towering Himalayan mountain range, it does
not contain any active volcanoes in that section of the country.
In fact, despite its size, India only has one active volcano.
The volcano in question is erupting right now, and it is gorgeous.
Imagine a stereotypical lush green tropical island with a volcano erupting on it, essentially
what I thought volcanoes looked like as a child.
Well, the Barren island volcano looks exactly like that, almost as if a childhood drawing
came to life.
This video will discuss the Barren Island volcano, and mention what its future hazards
are.
Although the Barren Island volcano is part of India, it is located closest to mainland
Burma and Thailand.
Specifically, this island is located 140 km northeast of Port Blair, and is a little more
than 500 kilometers west of Myeik in Maynmar.
Before I begin, I need to add a large disclaimer.
The geologic history and hazards of this remote island are NOT well known.
As a result, much of what I state in this video is based on very limited information,
and could turn out to be very wrong as more studies are done in the future.
From afar, this 3 kilometer wide island may look like a young and small volcano.
However, this couldn't be further from the truth.
More than 99% of this volcano is beneath the surface of the Indian Ocean, and it is quite
an OLD volcano.
The Barren Island volcano began forming around 1.8 million years ago, when a subduction related
volcano breached the deep seafloor.
These initial eruptions were relatively explosive, and started to build the volcano out of andesite
lava from a depth of 2,250 meters underneath the ocean surface.
After more than 1 million years of continuous activity, this large stratovolcano reached
climbed above the ocean surface.
Although we don't know exactly when this happened, we do know that this occurred more than 70,000
years ago.
After the volcano reached the ocean surface, eruptions simultaneously became less explosive.
Instead of producing andesite, the volcano now produced basaltic andesite and basalt.
These resulting eruptions would have been spectacular to witness, as they intermittently
ejected fluid bombs of lava every 15 minutes in what is termed a "strombolian" eruption.
On occasion, these eruptions also produced blocky flows of a'a' lava, which traveled
downslope, and further expanded the island.
By 65,000 years ago, Barren island was 3 kilometer wide, and had a summit which climbed to 700
meters above sea level.
It had the typical profile of a stratovolcano, much like the modern Mount Stromboli.
Then, for an unknown reason, the volcano became dormant for a period of several thousand years.
Underneath the island, the magma chamber continued to expand, which caused pressure to build.
Then, 61,000 years ago, this pressure was released via a plinian eruption.
In less than a week, the volcano erupted a volume of magma typically seen during hundreds
of years of activity.
As a 15 kilometer high plume of ash was carried into the atmosphere, the center of the volcano
collapsed, forming a 2 kilometer wide caldera.
In the aftermath of this eruption, the center of the island was now partially below sea
level, and was reclaimed by the Indian Ocean.
However, it did not take long for a new volcanic cone to emerge 300 meters the northeast of
the former summit.
Over the subsequent tens of thousands of years, this cone eventually reached the surface.
Once this occurred, the cinder cone continued to build upwards, and falling ash and lava
from its eruptions reclaimed much of the area lost by the caldera collapse.
Then, between 24,000 and 10,000 years ago, 4 large sub-plinian eruptions destroyed much
of the existing cinder cone.
The cinder cone which you see on the island today began forming in the aftermath of this
eruptive series 8500 years ago.
When an eruption on the island was first observed in 1787, the volcano had essentially the same
profile which it does today.
Between 1789 and 1852, 5 more distinct periods of activity were witnessed from this volcano.
Afterwards, the volcano became dormant for 139 years, until it erupted once again in
1991.
Since then, the Barren island volcano has been almost continuously erupting in a strombolian
manner with daily small scale explosions of lava and ash.
So, what hazards could this volcano pose in the future?
As long as no one decides to settle on the island, its frequent mildly explosive eruptions
shouldn't pose much of a hazard to anyone.
However, I still want to express a level of caution about this volcano.
On the edge of the island, you can make out a number of recent medium sized landslides.
It is quite possible that a similar sized collapse will occur in the future, generating
a local small scale tsunami.
Otherwise, the volcano is completely safe to visit, and is a popular destination due
to its beautiful coral reefs and wildlife.
I hope that you enjoyed this video.
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