Doomsday! Will a Supervolcano End the World?

Is this how it all ends?

The prime candidate for the next event is bubbling away on the border of Wyoming and Montana – Yellowstone National Park. During the late 1960s and 1970s, Bob Christiansen of the United States Geological Survey began to realize that instead of just an interesting valley full of hot springs, Yellowstone is actually the massive crater of one of the biggest volcanoes ever known. The Yellowstone caldera or “cauldron” is 34 miles wide and 45 miles long. Molten lava does not reach the surface, instead heats local groundwater, resulting in the spectacular geysers and hot pools.

Researchers say it blows its top every 600,000 years. The bad news is that the last eruption occurred just over 660,000 years ago.

Is this how it all ends?

In 1995, worries spread that Yellowstone’s massive crater was rising – like the sort of dome that preceded the Mount St. Helen disaster. But it sank back in 1997. Then it resumed rising with several new geysers appearing, then quit again in 2003. What made it rise? Some geologists speculate that highly explosive gasses and a large chamber of molten magma lurk beneath. Just the right geological shift – such as the park’s 1959 earthquake –could spark a massive blast blanketing most of North America in volcanic ash. Anyone living within 50 miles would be killed instantly. It is estimated that the last explosion sent 240 cubic miles of ash and pumice – that’s 1.1 trillion bushels -- skyward.

By comparison, the famous explosion of the volcanic Indonesian island of Krakatoa in 1883 released about 3 cubic miles of magma.

But there are other supervolcanoes lurking, waiting to blow their tops – and possibly end all life on earth? Unfortunately, yes.

Is this how it all ends?

The 1,080-square-mile Toba Lake Caldera in Indonesia is actually four enormous, overlapping craters and is sometimes described as Yellowstone's "big sister” – with the potential of even a larger blast. The most recent Toba supereruption, also called by geologists the “Youngest Toba Tuff” or simply “YTT” occurred between 69,000 and 77,000 years ago and is believed to have been one of the Earth's most catastrophic eruptions, plunging the planet into a 6-to-10-year volcanic winter and possibly an additional 1,000-year cooling episode. One theory says that it also resulted in the world's human population being reduced to as few as 2,000 adults, creating what anthropologists refer to as a “bottleneck” in human development in which our species almost suffered extinction.