Overview
- In a peer-reviewed study in Communications Earth & Environment, Kobe University researchers report a shallow magma-rich zone beneath Japan’s Kikai Caldera that indicates the system is recharging.
- The team, working with Japan’s marine research agency JAMSTEC, fired airgun pulses from a research vessel and recorded them with ocean-bottom seismometers to map the subsurface in high detail.
- Seismic tomography revealed a large low‑velocity anomaly consistent with molten rock at roughly 2.5 to 6 kilometers below the seafloor directly under the caldera.
- Geochemical differences between recent lavas and the 7,300‑year‑old Kikai‑Akahoya deposits, plus a central lava dome that has grown for about 3,900 years, point to newly injected magma rather than leftover melt.
- The authors say their magma re‑injection model may apply to other giant calderas such as Yellowstone and Toba, and they emphasize improved monitoring over time rather than any short‑term eruption forecast.