Say the word “supervolcano” and you’ll immediately think of Yellowstone and its violent past – but what about its future? When will the next super-eruption be?
The thing is, this is far from the only supervolcano on Earth, and many of them could easily rival the power of Wyoming’s own. So where are these supervolcanoes and which one of them really is the most dangerous in the world?
Let’s take a look, but here’s a spoiler for you – it's probably not Yellowstone.
What the Heck is a Supervolcano Anyway?
Spoiler alert – there’s no such thing as a supervolcano.
Supervolcanoes, as we colloquially know them, normally have a few common characteristics, including a massive cauldron-like crater (a “caldera”) and a vast magma source. Generally speaking, this moniker is casually attached to volcanoes that produce highly infrequent and intensely explosive blasts registering at the upper end of the Volcanic Explosivity Index (VEI).
And what, pray tell, is the VEI? Devised by a pair of inventive volcanologists back in 1982, it’s the only numerically standard way to define how “explosive” an eruption was by looking at a few criteria, including the ash plume height, the amount of volcanic material ejected, and how often this type of eruption occurs.
It’s not a perfect scale, but basically, VEI 0-1 events happen continuously all the time (see: Hawaii’s Kilauea) and produce lava slowly over time. They are almost never explosive. On the other end of the scale, VEI 7-8 events produce city-to-country-sized amounts of volcanic debris, very rapidly, once every 1,000 to 50,000 years.
In the last 36 million years, there have been 42 VEI 8 eruptions. Of these, some are considered to be super-eruptions made by supervolcanoes, while prolonged, continental outbursts of lava (see: Deccan Traps) do not seem to make the cut with most volcanologists.
So, yeah – pretty vague. It’s a term that’s essentially been popularized by both the media and organizations like the United States Geological Survey (USGS).
The Great Prismatic Spring in Yellowstone National Park. Lorcel/Shutterstock
Hide and Seek
All things considered, here’s a rough list of the world’s potentially dormant (not extinct) supervolcanoes:
1 – Yellowstone Caldera, Wyoming
2 – Lake Toba, Indonesia
3 – Taupo, New Zealand
4 – Campi Flegrei, Italy
5 – Long Valley Caldera, California
6 – Valles Caldera, New Mexico
7 – Aira caldera, Japan
So if you’re based in the US, your descendants might be in a spot of bother.