Effect of syneruptive decompression path on shifting intensity in basaltic sub-Plinian eruption: Implication of microlites in Yufune-2 scoria from Fuji volcano, Japan

►We investigated syneruptive time and condition that changed eruption intensity. ►We deduced magma decompression conditions from groundmass microlites of scoriae. ►Decompression rates in each eruptive unit have a positive correlation with intensity. ►Different rates had been generated before the start of microlite crystallization. ►Magmas erupted earliest and just after repose had been arrested in conduit.