Prehistoryc. 5300 BC · Kikai caldera, Kagoshima, Japan
Some Jomon communities grew after Japan's 7,300-year-old Kikai volcanic eruption
A Lund-led study finds the undersea blast made some regions uninhabitable, while northern Kyushu kept growing and distant regions stalled.
In brief 3 key points
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- A huge undersea eruption struck Jomon Japan about 7,300 years ago.
- Northern Kyushu kept growing while distant regions stopped growing.
- Why growth stalled far from the volcano is still uncertain.
A huge undersea eruption in Japan about 7,300 years ago did not hit all prehistoric communities the same way, a new study finds. Some populations shrank or vanished from the worst-hit areas. Others kept growing through the disaster and after it.
The volcano was Kikai-Akahoya, and it erupted around 5300 BC. An international team led by Lund University in Sweden studied how the eruption changed population patterns across Japan. The results are published in the journal Science Advances.
The lead author is Enrico Crema, a professor at the University of Cambridge. The senior author is Peter Jordan, professor in archaeology at Lund University. At the time of the eruption, Japan was home to Jomon communities, who lived by hunting and gathering.
“This eruption must have been devastating, exploding out of the seabed with little warning. It battered the Japanese islands with powerful earthquakes and enormous tsunamis, and then blanketed the landscape with meters of volcanic ash.”
Peter Jordan, professor in archaeology, Lund University
Archaeologists have argued for decades about what happened to the people living near the volcano. One view describes an almost complete apocalypse, with people abruptly gone from the areas closest to the eruption. Another holds that some communities survived even fairly close to it. The new study finds that neither account fully fits.
According to the team, the eruption badly damaged ecosystems and forced people from their homes. It made some regions uninhabitable. Yet some populations increased after it.
“The disaster caused major loss of life. However, survivors migrated, forged new social relations, innovated new kinds of economy, and appear to have found creative ways to exist and later thrive in the new post-disaster conditions.”
Enrico Crema, professor, University of Cambridge
Northern Kyushu kept growing
The team found sharp differences between regions. In southern Kyushu, Jomon populations had been shrinking long before the eruption. By the time it came, few people remained there. The region was mainly visited by highly mobile groups of foragers.
Northern Kyushu followed a different path. Its population was rising before the eruption, and growth continued through it and afterwards. This happened even though the ecosystems around it suffered extensive and lasting damage. The researchers suggest that people fleeing the worst-hit regions may have added to the growth.
Evidence also points to survivors who had lived inland moving towards the northern coast. Marine ecosystems there recovered fairly quickly and offered food. The team suggests that new ways of using the sea may have supported further growth.
Growth stalled far from the volcano
The researchers also found changes in parts of Japan much farther from the eruption. These regions had been growing before the catastrophe. Afterwards, their growth stalled or even reversed. According to the team, such widespread demographic effects had not been recognised before.
The researchers offer several possible explanations. The eruption may have disrupted the climate for a time across Japan. Deer and wild boar, two important Jomon foods, show severe tooth wear. This may be because the animals grazed in ash-covered country. Other volcanic effects on health and living conditions may also have played a part.
None of these causes is settled. The team concludes that a massive natural disaster can have effects well beyond the areas destroyed first.
Jordan says the results show that the effects of catastrophes are rarely straightforward. Communities facing overwhelming destruction can respond in different ways, depending on their circumstances and the choices open to them.
“Even in the most impossible situations, survivors and communities have choices, however limited: they need to act and make decisions; they need to adjust, collaborate, and find new connections and social networks.”
Peter Jordan, professor in archaeology, Lund University
Sources (1)
Peer-reviewed paperfrom Lund University and University of Cambridge
Paper: Enrico R. Crema, Mitsuhiro Kuwahata, Junzo Uchiyama, Ari Junno, Felix Riede, Peter D. Jordan. Divergent demographic responses to the Kikai-Akahoya volcanic catastrophe in mid-Holocene Japan. Science Advances, 2026; 12 (42). DOI: 10.1126/sciadv.aeh7197
Edited by Guiseppe Weijermars
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