Pada 11 Juni 1991ditugaskan satu tim pengukuran situasi topografi gunungapi ke . Gamalama. Kabupaten Maluku Utara, profinsi Maluku. Tim pengukuran terdiri dari Rochanan dan Agus Martono dengan SPPD No.355/0441/3402/1991 dan 356/0441/3402/1991. Pelaksanaan perkerjaan selama 36 (tiga puluh enam) hari termasuk perjalanan selama 6 (enam) hari.
Mount Umsini ("Oemsini") is internationally listed as an active volcano in the Bird's Head Irian Jaya (New Guinea)/ The mountain occurs at the north end of the Arfak Mountains, a range consisting of tilted and presumably folded early Tertiary turbidite sequences and volcanoclastic rocks that were intruded by Early Oligocene gabbroic rocks. The morphology is characterized by NNW-striking, long, …