Supervolcanoes: Not Just a B-Movie Plot Device

Natural disaster movies just keep cropping up. If there is a way the world could possibly end, there is probably a movie about it. While the movies themselves tend to be overdramatized to the point of ridiculousness, they generally do have real-life sources for inspiration. Recently, the commonly used plot point of a supervolcano has been popping up in news stories as well as in the theaters.

The word “supervolcano” sounds like something that should only be found in a sci-fi adventure, but it is a recently established term that is actually used in scientific speech and writing. Because it is such a new term, there is not a set definition for what qualifies as a supervolcano; however, the term is always used to identify those volcanoes on Earth capable of the largest eruptions (often called supereruptions).

To put this into perspective, a recent article published in Nature defines a supereruption as anything that ejects over 500 cubic kilometers (km) of eruptive material (which includes ash, lava, and anything else that comes out of a volcano). Mount St. Helens in the state of Washington is famous for erupting in 1980, causing quite a bit of damage, and resulting in 57 casualties. That eruption produced about 1.3 cubic km of material. Not only this, but 500 cubic km is the minimum amount required by this definition. Some people hold that a volcano needs to erupt at least 1000 cubic km of material if it is to be considered a supereruption. The consequences of such an eruption would be catastrophic. Besides the initial explosion causing massive amounts of damage, that amount of material is enough to spread throughout the Earth’s stratosphere. This could cause sunlight to be reflected and the world to plunge into a “volcanic winter”, an event where the global average temperature cools and weather patterns become disastrously unpredictable. Volcanoes capable of producing eruptions of this magnitude are scattered around the world, and I’ve seen two in the news recently: Kikai caldera near Japan and Yellowstone.

Yes, beloved Yellowstone National Park sits on top of one of the most massive volcanoes in our world. It is actually ranked second largest, only smaller than Toba in Indonesia. Yellowstone also happens to be incredibly active. All of the geysers, mud pots, hot springs? They are just signs of the reservoir of magma trapped under the surface. The current news attention is due to Yellowstone experiencing earthquake swarms, an event where many earthquakes of small magnitude happen over a short time span. The current swarm produced 200 earthquakes in 10 days. This has caused some people to worry, which is understandable. However, there is good news! These earthquake swarms are just another sign of the stresses on the land in that area, and they are common. This may not reassure everyone, but think about it like this. Old Faithful is a geyser people flock to everyday to (perhaps unwittingly) gaze at the splendor of this supervolcano. If the volcano wasn’t there, Yellowstone wouldn’t be known worldwide for its beauty and wonder. The earthquake swarms are just another reminder of what makes Yellowstone unique.

Even the news on the Kikai caldera does not need to cause fear. This particular supervolcano is located underwater, south of Kyushu Island in Japan. Researchers have discovered a volcanic dome that has built up in the caldera (a large crater) of a previous supereruption. If this dome decided to erupt, it would be disastrous. This, however, is very unlikely to happen anytime soon. The reason why attention is being placed on this volcano now is pure curiosity and planning on the part of geologists. They want to track and understand potential threats such as the dome in the Kikai caldera. The more that is known, the better humanity is prepared for if it does erupt.

This is the case worldwide. Every earthquake swarm in Yellowstone is recorded, measurements are constantly being taken. We try to prepare for an eventuality that is very unlikely to ever occur in our lifetime. Supervolcanoes may show signs of activity like Yellowstone, but their supereruptions are incredibly rare. Most of the time, eruptions from supervolcanoes do not qualify as supereruptions. They are still dangerous, but not catastrophic. These relatively smaller eruptions are also very uncommon, as supervolcanoes can go many thousands of years between eruptions. Nature does not follow a schedule, and does not care if people think an eruption is overdue or not. So, researchers continue to monitor and speculate, and we all can put the fear of an imminent supereruption to the back of our minds. Instead, we can focus on more pressing matters, such as midterms or the next cheesy disaster movie to come to theaters near you.

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