A submerged supervolcano off the coast of Japan could erupt and kill 100 million people, according to a terrifying study.
Scientists have discovered evidence of a rising six-mile wide dome of lava in a collapsed magma chamber of the Kikai Caldera – a giant cauldron-like depression among the Osumi Islands.
Experts believe it contains 32 cubic km (7.68 cubic miles) of magma. And distortions on its surface suggest it is ready to blow.
A study , conducted by researchers with the Kobe Ocean-Bottom Exploration Center (KOBEC) at Kobe University, confirmed the giant lava dome was created after a caldera-forming supereruption 7,300 years ago.
The sudden explosion is believed to have wiped out prehistoric civilisations in southern Japan.
If the new lava dome erupts, it could eject huge amounts of debris into the atmosphere, potentially blocking out the sun and triggering a ‘volcanic winter’.
It could also cause tsunamis that would hit southern Japan and the coasts of Taiwan and China, before striking the coasts of North and South America.
Professor Yoshiyuki Tastsumi, head of KOBEC and a magma specialist, as well as the first author of the study, told The Mainichi newspaper: "Although the probability of a gigantic caldera eruption hitting the Japanese archipelago is one percent in the next 100 years, it is estimated that the death toll could rise to approximately 100 million in the worst case scenario."
Researchers discovered several intrusions on the surface of the dome, leading them to believe lava is building up underneath the dome.
They also spotted super-heated water columns, near the dome’s crust.
KOBEC has carried out six underwater geological surveys using submarine robots which analyse rocks, seismographs and electromagnetometers.
Researchers are to return in March this year.