The Bible's Book of Revelation warns of "a great earthquake" when "the sun became black as sackcloth of hair." Could this be caused by the eruption of a supervolcano?

Geologists and earth scientists are keeping a close watch on a supervolcano at Yellowstone National Park in Wyoming and Montana—right at the heart of the United States' northwest—which they say can kill some 90,000 people in an instant if it erupts.

This volcanic eruption can also trigger a nuclear winter, since such a natural disaster can spew layers of molten ash up to 10 feet high into the atmosphere, spreading 1,000 miles from the park.

Scientists warned that this ash buildup "would block off all points of entry from the ground, and the spread of ash and gases into the atmosphere would stop most air travel, just as it did when a much smaller volcano erupted in Iceland in 2010."

Sunlight is also likely to be dimmed if the Yellowstone supervolcano erupts due to sulphuric gases from the eruption, which will mix with water vapour in the air.

"The haze of gas that could drape the country wouldn't just dim the sunlight — it also would cool temperatures," the scientists warned.

Thankfully, the chances of a volcanic eruption of such magnitude is extremely slim. Scientists say there is a one in 700,000 annual chance of a volcanic eruption at the Yellowstone National Park.

These apocalyptic scenarios began forming after geologists discovered a second gigantic magma chamber beneath the Yellowstone volcano last April. This magma chamber is so large that it can fill up the Grand Canyon 11 times over.

The Yellowstone supervolcano has remained dormant for more than 70,000 years now. It is considered to be one of the largest active continental silicic volcanic fields in the world, which means that it is rich in magma and igneous rocks.