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Volcanoes are one of the most powerful forces on Earth. Their lava can destroy cities and their ash clouds can blot out the sun. And there is basically nothing we can do to make sure a volcano will never erupt again, except wait for it to die. So, while we wait, what is it exactly that kills a volcano? Hi, I'm Cameron and this is Minute Earth. There are three main ways a volcano can die, and the first is if its supply of magma fizzles out. The pushing together or pulling apart of tectonic plates can cause magma to form. But when those plates fuse together, the magma forming activity stops, snuffing out the volcano. Poland's Kaczawskie Hills and Foothills has a whole national park devoted to volcanoes that suffered this fate. Locals call it the land of
extinct volcanoes. The second way a volcano can die is if it gets dragged away from its magma supply. Sometimes weird conditions in specific places can melt the mantle, sending up a plume of melting mantle rock known as a hotspot that pools beneath the crust and can birth a volcano. That hotspot itself doesn't ever move, but the Earth's crust above it does. So, the volcano will eventually leave its magma supply behind. But since the hotspot itself is still there, when one volcano dies in this way, a new one might form next to it, and then a new one forms next to that, and so on. The Hawaiian Islands, for instance, are the newest volcanoes formed by a hotspot that has left a trail of dead volcanoes that
stretches all the way to Russia. The third way a volcano can die is if it gets clogged. Like if conditions in the mantle change and the magma flow slows down, the magma that's already in the volcano's vents can cool, hardening into a giant plug. 50 million years later, that plug might be all that's left of the volcano. Or, if the volcano's vents somehow get damaged, the magma might not be able to escape. In these cases, the remaining magma will often find its way to a different spot nearby where it can escape. That's likely what happened when, in a spectacular eruption, the largest ever actually, a volcano called Toba clogged itself. Evidence suggests that the magma from its chamber got rerouted to nearby
Sinabung, which is still active today. Of course, it's really, really hard to tell exactly what's going on underneath a volcano, so we're not always sure what has happened to a volcano. In fact, sometimes it's hard to tell whether a volcano is actually dead. Uturuncu in Bolivia hasn't erupted in 250,000 years, so scientists assumed it was long gone. But recently, it started rumbling again, suggesting the possibility of future volcanic activity. It turns out that Uturuncu and other quiet volcanoes like it might not be dead after all. Instead, they could be taking magnifcently long naps.
