Eruptive activities of Tsurumi volcano in Japan during the past 30, 000 years

Abstract

Tsurumi volcano located in northeastern Kyushu, Japan is the stratovolcano which consists mainly of lava domes and lava flows. Several tephra layers from the volcano are also distributed on its flank. In this paper, the eruptive activities of Tsurumi volcano during the past 30, 000 years are examined by tephrochronology and radiocarbon dating. Furthermore, the eruptions during historical time are considered. During 29∼7.3 cal ka BP, the lava flow eruptions occurred repeatedly at Tsurumi volcano. In the 10.5 cal ka BP eruptions, block-and-ash-flows were generated by dome collapse. Subsequently, small-scale eruptions without lava flowage occurred in 1.8 cal ka BP, 1.2 cal ka BP and 1.0 cal ka BP. In historical time, eruptive phenomena were recorded in AD 711 and 867. Judging from geological data and interpretation of ancient documents, we estimate that these events correspond to 1.2 cal ka BP (probably 711 AD) and 1.0 cal ka BP (probably 867 AD) phreatic eruptions at Garan-dake, respectively.