Sequence of the 1895 eruption of the Zao volcano, Tohoku Japan

► We revealed the eruption sequence of 1895 eruption of Zao volcano in Tohoku Japan, as well as 1894 precursory eruptions. ► Mode of emplacement of each eruption was examined by geologic data and documents. ► Eruptions occurred at February, March, August and September in 1895, which became bigger toward September climactic eruption. ► Ascent of andesitic magmas would trigger the eruption of the sub-volcanic hydrothermal altered materials. ► Crater diameter and eruptive energy of the climatic eruption were also estimated.