Fig. 1

Kawah Ijen phreatic eruption and seismic network. a Kawah Ijen location in South East Asia. b Seismic stations locations in the crater (POS and DAM are broadband seismic stations, whereas KWUI and TRWI are short-period seismic stations). c Photograph taken on 11 March, 9 days before the phreatic eruption on 20 March 2013 (the persistent degassing is emitted by the fumarole). d Photograph taken on 27 March 2013, 7 days after the eruption. The arrow indicates a common feature on the photos