On the 9th February, a team of volcanologists from the University of Kobe confirmed a worrying discovery. A pocket of magma has formed under the Kikai caldera, the area which is responsible for one of the biggest eruptions of the Holocene era. This is a development which could be a warning sign for a dramatic event: a huge eruption that could cause repercussions that would affect not far off 110 million people.
An ancient evil awakens
The Kikai caldera is a concealed evil found in Japanese waters. It is the last remaining evidence of an event that devastated a great part of the archipelago around 6,500 to 7,300 years ago: the eruption of Akahoya, one of the biggest eruptions that occurred during the Holocene period (about 8,000 years previous to our era today). Nearly 150 cubic kilometers of ejecta were projected from the smoking crater during this cataclysmic event that reshaped some of the Kyushu island vegetation.
That is why this recent discovery of a 32 cubic kilometer supply of magma under the giant caldera is not a comforting one. According to scientists, the magma’s chemical signature indicates that is it not leftover from the Akahoya eruption, but rather a new build up under the surface of the gaping crater.
“The post-caldera activity, at least which concerns the [Kikai] caldera, should be seen as a preparation stage before the next big eruption” claims the volcanologist Yoshiyuki Tatsumi, main author of the study. “This is not a peaceful period after the Akahoya eruption.”
Japan is holding its breath
There is 1% chance that a giant eruption the size of the one that caused the caldera eruption will occur at some point in the next 100 years. This is an undeniable risk that forces researchers to be on alert. “An eruption like this means a single blast of more than 40 cubic kilometers of magma, which would cause terrible damages. The mechanism behind this event and how to prevent it are still pressing issues,” they claim.
During their next trip in March, the team wanted to use seismic surveying and underwater robots to obtain a lot of information about its current state and how the caldera is forming. This research should allow them to fully understand the mechanisms that would cause the super eruption to be triggered.
“Super eruptions leading to massive collapses at the base of the caldera are rare events yet extremely dangerous and also have serious consequences such as the threat of a ‘volcanic winter’. Many super volcanoes can have repetitive super eruptions over the millions of years that they exist,” explains the researchers in their article.
This discovery offers the scientists a priceless opportunity to better understand the dynamics of these super eruptions, but the price of this window into one of the most devastating events in history is very high. Until new details are obtained on the risks involved, the population of Japan should hold its breath, in the hope that the caldera will stay quiet for the centuries to come.