Did you know that Yellowstone National Park is a massive, active volcano? What’s more, it’s a supervolcano! Within the past two million years, the Yellowstone region has seen three massive eruptions.
The term “supervolcano” refers to volcanoes which have had at least one explosion that released more than 1,000 cubic kilometers of magma. Such eruptions rank at level 8 — the highest ranking on the Volcanic Explosivity Index (VEI).
There are about 20 known supervolcanoes on Earth, and the most recent large-scale eruption of a supervolcano happened about 27,000 years ago.
The good news is that super-eruptions are very rare events and occur only once every 100,000 years on average. But the bad news is that super-eruptions are hundreds of times larger than the violent eruption of Krakatoa in 1883 which sent shockwaves and tsunamis and caused temperatures to drop all around the world.
The 1815 eruption of Mount Tambora in Indonesia was the largest in recorded human history and had serious global consequences. The following year became known as “the year without a summer”. The vegetation was killed off because of the falling ash, and people were starving. But that devastating blast wasn’t even a super-eruption.
Just imagine the effects of a supervolcano explosion. Sharp volcanic ash blown out of the craters would damage buildings and vehicles, kill animals and humans. Moreover, some of the volcanic ash and gases would stay in the atmosphere blocking out the sun and resulting in climate cooling, crops failing and people starving.
No wonder there has been a lot of speculation that when Yellowstone explodes, it will be able to wipe out humanity.
Yellowstone is indeed an active volcano. There are plenty of hot springs, geysers and steaming mud pots in Yellowstone National Park all caused by the massive amount of heat underground. Frequent minor earthquakes, ground moving up and down — all that reveals activity below ground.
However, Michael Poland of the Yellowstone Volcano Observatory states that there are no signs of an upcoming eruption. The volcano will probably give us decades of warning (large earthquakes, significant ground moving, heat intensifying). And even when it does happen, the most likely activity would be lava flows with minimal direct effect outside Yellowstone National Park.