The Kikai Caldera, located south of Japan’s main islands, devastated a large swath of the Japanese archipelago when it spewed more than 500 cubic kilometers of magma during the Akahoya eruption some 7,000 years ago. Now, a team of scientists from the University of Kobe (Japan) has just confirmed the evidence of new volcanic activity below the crater.
Researchers have detected a giant lava dome beneath the Kikai caldera, which contains a volume of more than 20 cubic kilometers of magma, an accumulation that could reveal clues to the next super eruption that Kikai may unleash.
An upcoming supereruption?
According to previous research by volcanologist Yoshiyuki Tatsumi, given Japan’s level of active volcanism, there is about a 1% chance that a “catastrophic” caldera eruption will occur within the Japanese archipelago at some point during the next 100 years. an event that could endanger or end the lives of millions of people.
Such eruptions do not appear very often in history, but they do happen, as the Kikai Caldera experienced two such incidents prior to the well-known Akahoya eruption: one about 95,000 years ago and the other about 140,000 years ago.
Confirmation of this lava dome, detected through three separate survey trips, underwater robot observations, and seismic reflection analysis, does not mean that any type of super eruption is necessarily imminent, but the researchers suspect it is evidence that we cannot ignore.
The lava dome is a circular mound that originates from a slow eruption of viscous lava from a volcano.
This volume of hot, viscous rock, about 600 meters high and covering a width of 10 kilometers, is not an echo of Akahoya, since the lava dome is chemically different from the super-eruption of Akahoya, but we shows that something new is taking shape under the East China Sea.
What this volcanic activity portends is unclear at the moment , and at least one researcher has pointed out that we could be looking at a congregation of smaller lava domes, as opposed to a giant mass combined.
To further investigate, Tatsumi and his colleagues will embark on another expedition to the Kikai site next month, to conduct further analysis and hopefully get a clearer idea of the magma activity fueling the evolution of this caldera. .
Reference: Yoshiyuki Tatsumi, Keiko Suzuki-Kamata, Tetsuo Matsuno, Hiroshi Ichihara, Nobukazu Seama, Koji Kiyosugi, Reina Nakaoka, Kazuo Nakahigashi, Hideaki Takizawa, Kazuki Hayashi, Tatsuro Chiba, Satoshi Shimizu, Mamoru Sano, Hikisamaru Iarumi Haruisamaruu, Hijamaru Iruikarumi Sugioka & Yojiro Yamamoto. Giant rhyolite lava dome formation after 7.3 ka supereruption at Kikai caldera, SW Japan. Scientific Reports volume 8, Article number: 2753 (2018) doi: 10.1038 / s41598-018-21066-w
