Submarine cores record magma evolution toward a catastrophic eruption at Kikai Caldera

Magma evolution toward a caldera-forming eruption remains uncertain due to a lack of successive volcanic records. This study analyzes a submarine core near Kikai Caldera, Japan, which recorded two caldera-forming eruptions and smaller eruptions between them. The discovery of mafic glass fragments in the 95-ka eruption deposits suggests mafic magma involvement. Inter-caldera activity showed binary mafic and felsic magma extrusions, shifting to felsic dominance. The final stage before the 7.3-ka eruption lacked the most felsic composition, suggesting felsic melt accumulation for the next catastrophic event.

Takeshi Hanyu, Nobukazu Seama, Katsuya Kaneko, Qing Chang, Reina Nakaoka, Koji Kiyosugi, Yuzuru Yamamoto, Tetsuo Matsuno, Keiko Suzuki-Kamata, Yoshiyuki Tatsumi