Kikai boiler
About 7,300 years ago, a volcano off the island of Kyushu, Japan, triggered what remains the largest known eruption of the Holocene, our current geological epoch.
In a new study, at the end of March by Kobe University (Japan), researchers reveal how the enormous magmatic chamber of the volcano Kikai boiler is slowly refilling.
7,300 years ago, this volcano ejected about 160 cubic kilometers of dense rock equivalent during its Akahoya eruption – more than 11 times the volume expelled by Novarupta in 1912 and 32 times that of Pinatubo in 1991.
As , the violent explosion expelled material across 4,500 square kilometers, an area many times larger than London, and sent pyroclastic flows up to 150 km from the epicenter. Tephra fell over large areas of Japan and the Korean peninsula.
The volcano hasn’t done anything remotely this dramatic since. However, it remains active, producing a scattered set of small eruptions in recent decades.
Previous investigations have found evidence of new volcanic activity beneath the Kikai Caldera, pointing to the formation of a lava dome and raising concerns about its potential to erupt again.
The Akahoya eruption is believed to has devastated the Jomon peoplewho inhabited what is now Japan between about 14,000 BC and 300 BC.
Much has changed over the past seven millennia, and given the region’s current population density, another eruption – even a relatively modest one – could be much more devastating.
The Kikai Caldera is now mostly submerged under the ocean, limiting access but also preserving traces of past eruptions and helping modern studies of them.
