That's 1/76th of the world's current population of 7.6 billion as of December of 2017.
Okay... but how likely is it to actually erupt and kill all of these people? Scientists peg that percentage at a measly one percent.
Uh... that's actually quite high, if one actually thinks about it.
And just how accurate is that one percent number? It's not like scientists can actually predict when or where or how hard a volcanic system will erupt!
The lava dome, which is inside an underwater volcano was discovered by the Kobe Ocean-Bottom Exploration Center (KOBEC), locating it approximately 50 kilometers (~30 miles) south of the Satsuma Peninsula in Kagoshima Prefecture.
The lava dome is about 610 meters (2,000 feet) high and 9.66 kilometers (six miles) in diameter... so it's a big mammajamma.
Kagoshima Bay itself is actually something called the Aira Caldera (姶良カルデラ, Aira-Karudera). A caldera, as opposed to a volcanic crater, is a huge depression in the ground which formed after a previous supervolcanic eruption. As the magma chamber emptied, the ground above sank in and partially filled the hole left behind.
According to KOBEC head professor Tatsumi Yoshiyuki (surname first) in speaking to Japan newspaper The Mainichi: “Although the probability of a gigantic caldera eruption hitting the Japanese archipelago is one percent in the next 100 years, it is estimated that the death toll could rise to approximately 100 million in the worst case scenario.”
Does that imply that it's at two percent over the next two hundred years, or is it like the way we measure earthquakes, and go up by a level of 10 per 0.1 magnitude?
And really - again - one percent over the next 100 years... so it could be the next 10 years, and an even higher percentage...
While an ordinary volcano is triggered (we think) by internal mechanisms such as magma pressure build-up up over time, whereby it punches through the rock....
A supervolcano is triggered by going's on above the Earth’s crust.
Considering it has a large magma chamber below it, just its weight alone can cause it to become unstable and to form cracks and faults.
Via the faults, magma can create a chain reaction that could lead to an explosion which could extinguish a whole lotta life on the planet... maybe even all life.
So how can you tell when a supervolcano will explode? You can hazard a guess... and that's all.
And for all you hypochondriacs out there, there's a supervolcano out in the U.S., as well. Out in Yellowstone National Park, where that self-same volcanic system last erupted 600,000 years ago... and while a volcano is usually considered to be extinct if it has blown up in 10,000 years, the Yellowstone National Park is a hub of volcanic-like activity.
Ever heard of Old Faithful, the hydrothermal geyser that erupts like clockwork every few hours?
That's part of it.
|Grand Prismatic Spring, one of the geothermal features of the Yellowstone Caldera. Photo by Brocken Inaglory/Wikimedia CC-by-SA 3.0|
But it's not ready to explode just yet... it takes a few decades for the volcanic system to become hyper enough to explode in an eruption.
Scientists do not believe that the Yellowstone supervolcano will erupt for at least another 1,000 years.
But again... how do you know?
There's also a supervolcano in Long Valley, California, one in New Mexico, one in Sumatra Indonesia, one around the North Island New Zealand, and one under Naples Italy.
Nowhere is a safe spot. Maybe Africa. Yeah... the cradle of humanity... but the southernmost part.
Okay, so some 100 million people could die if the Japan Kagoshima supervolcano erupts... how do we know that?
After the explosion comes severe pyroclastic flows of a fluidized mixture of solid and semi-solid fragments of rock, ash and incredibly hot expanding gases which act similarly to a snow avalanche.Have you ever seen the "statuary" of Pompei?
The casts of the corpses of a group of human victim of the 79 AD eruption of the Vesuvius, found in the so-called “Garden of the fugitives” in Pompeii. Image by
|This map refers to the fall out from a possible Yellowstone volcanic eruption. For reference in gold, is the spread of ash from Mount St. Helens back in 1980.|
Should you have survived this onslaught, next comes the winter that never ends, as ash enters our atmosphere and effectively acts as a shield blocking out the warming rays of the sun... dropping the temperature on the planet, as well as effectively stopping plant growth...
Anyhow... you can see a teeny tiny video below describing the Japanese supervolcano.... though you probably will have learned more just from reading the above....
You're gonna need Sunscreen 2 billion, I think.