Underwater magma chamber ‘could kill 100 million people’
from the article at https://www.rt.com/news/419097-volcano-super-eruption-japan-kikai/
"A magma reservoir potentially hidden behind an underwater volcanic crater could have civilization-ending results if it ever erupts, according to Japanese scientists.
Experts from the Kobe University Ocean Bottom Exploration Center (KOBEC) have confirmed that a giant caldera or large crater exists in the Japanese Archipelago. The crater, measuring 32 cubic kilometers, is said to be the largest of its kind and the result of an explosive underwater eruption 7,300 years ago, according to their latest study.
Sitting between the Pacific and Philippine Sea Oceanic plates, Japan is a hotbed for seismic activity, which is why scientists are keen on updating methods of predicting natural disasters. The KOBEC team has been carrying out detailed surveys of the area and published their findings in Scientific Reports.
Although the probability of a gigantic caldera eruption hitting the Japanese archipelago is 1 percent in the next 100 years, it is estimated that the death toll could rise to approximately 100 million in the worst case scenario,” professor Yoshiyuki Tatsumi, head of KOBEC, told The Mainichi.
Super eruptions are rare, with Yellowstone Volcano Observatory scientist Michael Poland telling RT.com that the odds of civilization-ending explosion is “astronomically small.” However, scientists researching the Kikai caldera believe that a giant magma reservoir may lay hidden below the crust - and an eruption could be deadly."