The Akahoya eruption was the strongest known

volcanic eruption Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often ...

of the

Kikai Caldera (alternatively Kikaiga-shima, Kikai Caldera Complex) is a massive, mostly submerged caldera up to in diameter in the Ōsumi Islands of Kagoshima Prefecture, Japan. Geology Caldera formation has been dated from about 95,000 years ago and has in ...

Kyūshū is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surround ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

. It ejected about of volcanic material, giving it a Volcanic Explosivity Index of 7.

Retrospective dating

Archaeologically it has been dated around 7,300 cal. BP during the earliest stage of the

Jōmon period The is the time in Japanese history, traditionally dated between 6,000–300 BCE, during which Japan was inhabited by a diverse hunter-gatherer and early agriculturalist population united through a common Jōmon culture, which reached a c ...

, but it had also been uncorrected

radiocarbon dated Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was dev ...

to as recent as 6,500 BP. The current accepted dating adjustment from multiple other sources is about 7,200 to 7,300 years ago.

Aftermath

This eruption has been linked to the end of the initial Jōmon culture in southern

although impact, although marked, was not as great as some commentary had suggested with Nishinozono sub-type pottery tradition, that had started prior maintained throughout and after the eruption sequence in Kyūshū. It took nearly 1000 years to recover. Jōmon who lived further away survived such as on northern Kyūshū,

Honshū , historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island separa ...

and

Hokkaidō is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel. The la ...

but likely had to revert for a period to maritime food sources mainly. The fate of the initial Jōmon culture on south Kyūshū does not quite parallel the demise of the

Minoan civilization The Minoan civilization was a Bronze Age Aegean civilization on the island of Crete and other Aegean Islands, whose earliest beginnings were from 3500BC, with the complex urban civilization beginning around 2000BC, and then declining from 1450BC ...

, which may have ended as a consequence of another massive volcanic eruption. However these events give more credence to cultural traditions that maintain stories of established cultures vanishing quickly and completely, since it is known to have happened in (

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...

) human history, in two very different parts of the world. The events also call for deeper study into the effects of volcanic activity on human cultural development.

References

Volcanoes of Kyushu Volcanic eruptions in Japan Prehistoric volcanic events VEI-7 eruptions Plinian eruptions Jōmon period {{Japan-hist-stub