The very thought of volcanos erupting is enough to scare many. So imagine what happens when a volcano that erupted 7,300 years ago makes a comeback? The result is as disastrous as you imagined it would be. Japanese researchers fear that an underwater supervolcano off the coast of Japan could blow and kill 100 million people. The scientists have discovered evidence of a giant dome of lava created 7300 years ago in the Kikai volcano’s collapsed magma chamber. The submerged dome contains about 32 cubic km (7.68 cubic miles) of magma, and distortions on its surface suggest the dome is growing. What scarier is the fact that an eruption could take place without warning, and if it does, it could kill as many as 100 million people and trigger a ‘volcanic winter’, state scientists.
At present, the dome is around 6.2 miles (10 kilometres) wide and 1,968 feet (600 meters) tall. The study has been conducted by researchers with the Kobe Ocean-Bottom Exploration Center (KOBEC) at Kobe University. Daily Mail reports that the giant lava dome was created after a caldera-forming supereruption 7,300 years ago. That eruption, scientists believe, wiped out the prehistoric Jomon civilisation in southern Japan. The Sun quotes the researchers stating that if the new lava dome erupts, it could eject huge amounts of debris into the atmosphere, potentially blocking out the sun for some areas to trigger a ‘volcanic winter’. A tsunami could also be caused in southern Japan and coasts of Taiwan and China and eventually strike coasts of North and South America.
The researchers add that such supereruptions are ‘rare but extremely hazardous events, and also have severe global impacts. The study notes that many of these super-volcanoes repeat super-eruptions in their multi-million-year histories. Scientists who discovered the evidence of the dome have said that it is hissing toxic gas. It is in a ‘caldera’, i.e. a bowl-shaped depression which forms when a volcano collapses into itself. Discovery of several intrusions on the surface of the dome led the researchers to believe that lava is building up underneath the dome. They also spotted super-heated water columns, near the dome’s crust. So far, KOBEC has carried out six underwater geological surveys using submarine robots which analyse rocks, seismographs and electromagnetometers.