Science & Tech · Science & Environment · 16 hrs ago
Ancient Japan’s volcanic eruption had varied effects on populations
About 7,300 years ago, the Kikai-Akahoya volcano erupted near Japan, sending earthquakes, tsunamis and ash across the islands.
The area was home to Jomon hunter-gatherer communities, whose lives depended on local food and ecosystems.
Researchers found that the eruption’s effects varied across Japan: southern Kyushu’s population had already been shrinking, while some regions were badly damaged and people were forced to leave.
In northern Kyushu, population growth continued through and after the disaster, possibly helped by people fleeing more severely affected areas.
Some survivors moved inland to the northern coast, where marine ecosystems recovered relatively quickly and provided food.
Farther from the volcano, population growth stalled or reversed; possible causes include climate disruption and changes affecting deer and wild boar, but the study does not establish a single explanation.
The findings show the disaster neither wiped out all nearby communities nor left them untouched, and researchers say survivors adapted through migration, new social ties and changing economies.
The Kikai-Akahoya eruption about 7,300 years ago caused population changes across prehistoric Japan, but its effects varied by region.
Researchers found population decline, migration, adaptation and growth rather than a single nationwide outcome.
Southern Kyushu’s population had been shrinking before the eruption, while growth in northern Kyushu continued through and after it.
Some survivors moved toward northern coastal areas, where marine ecosystems recovered relatively quickly.
Population growth also stalled or reversed in regions farther from the volcano, possibly due to climate disruption or changes affecting food sources.
- Who
- Jomon communities across Japan were affected; an international research team led by Lund University studied the population changes.
- What
- The Kikai-Akahoya eruption had varied effects, including population decline, migration, adaptation and growth.
- When
- About 7,300 years ago.
- Where
- Japan, including southern and northern Kyushu and regions farther from the volcano.
- Why
- The eruption damaged ecosystems and displaced people; possible wider effects include temporary climate disruption and changes affecting food sources.
Near-total population collapse theory
Survival close to the eruption theory
Population outcome
Near-total population collapse theory
Communities near the eruption almost completely disappeared.
Survival close to the eruption theory
Some communities survived even relatively close to the disaster.
Southern Kyushu’s population was shrinking, while northern Kyushu’s population was growing.
The Kikai-Akahoya volcano erupted beneath the sea, damaging ecosystems and forcing people from their homes.
Northern Kyushu’s population growth continued, while growth in some more distant regions stalled or reversed.
- Eruption
- Kikai-Akahoya
- Age
- About 7,300 years
- Southern Kyushu
- Population shrinking before the eruption
- Northern Kyushu
- Population growth continued through and after the eruption
- Research lead
- Lund University
3 sources
What people are saying
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.
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.