Volcanic eruptions are measured using the Volcanic
Explosivity Index, or VEI, which was developed in 1982 by Stephen Self of
the University of Hawaii and Chris Newhall of the US Geological Survey. The
scale generally runs from 0 to 8, with 0 being a non-explosive eruption and 8
being the biggest eruptions in history. I get the impression there could be
bigger eruptions than that, but we might be too dead to measure them.
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| Kablooie |
I’m not even joking. The last VEI 8 eruption was the Oruanui eruption,
which happened 26,500 years ago, and created Lake Taupo, the largest lake
by surface area in New Zealand (with a surface area of 238 square miles or 616
square kilometers). The last one before that was the Toba event,
which occurred between 69,000 and 77,000 years ago and is believed to have
caused a volcanic winter up to 10 years long and 1,000 years of global climate
change. It has also been linked to a genetic bottleneck in human evolution,
which occurred about 70,000 years ago when the human population of the entire
world dwindled to between 3,000 and 15,000 people. This could explain why there’s
so little genetic diversity among humans today. Or, you know, it could all be
bullshit. Those scientists, always kiddin’ around.
The Krakatoa eruption of 1883 was a VEI 6, and emitted six
cubic miles (25 cubic kilometers) of...ashes and stuff. In case you’re not
familiar with that one, it’s the one that blew up a whole island in Indonesia.
Oh, wait, I just checked Wikipedia and it turns out it was only two-thirds of
the island. That’s another thing my mother lied about.
The eruption killed 36,417 people (that seems like an
awfully specific number, don’t you think?) and was heard 3,000 miles (4,800 km)
away. Also, it was before cameras were invented, but not to worry, there was a
sketch artist on the scene:
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| Kablooie |
My mother also used to talk a lot about the Mount Saint
Helens eruption of May 1980, which is odd because she wasn’t there, and also I’m
starting to think my mother has an unhealthy obsession with things that
explode. A 5 on the VEI scale, Mount Saint Helens had lain dormant for more
than 100 years before a late March earthquake caused it to start venting steam.
By late April, the mountain had “grown into a bloated, trembling blister of
rock and magma” in
the fascinatingly grotesque words of an unnamed Discovery News writer. Shit,
I hope they’re paying you well, kid.
When “the blister popped” on 18 May 1980, the entire north
face of the mountain collapsed into what would be the largest avalanche of debris
in recorded history. The pyroclastic flow would flatten everything within 230
square miles (600 square km). Ash spewed forth from the volcano for over nine
hours, reaching a heights of up to 16 miles (27 km) and raining down as far
east as Edmonton, Alberta, Canada.
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The explosion of Huaynaputina
(don’t ask me how to pronounce that) in Peru in 1600 sent lahars (volcanic
mudflows) 75 miles (120 km) away into the Pacific Ocean and may have caused some of
the coldest global temperatures in 500 years. In fact, this VEI 6 explosion
may have been responsible for the Russian famine of 1601-1603 that saw the
ouster of the reigning Tsar. What we do know is that the sketch artist on this
scene really should have been fired:
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| WTF is this? Where's the kablooie? |
