Diantara gunung-gunung berapi di Indonesia G. Merapilah yang paling aktif. Kalau kita melihat sejarah kegiatannya sejak tahun 1991 maka gunung api tersebut dalam jangka waktu 72 tahun lebih banyak bekerja daripada tidak.. Kecuali menurut kenyataan bahwa G. Merapi sering bekerja dan hampir tiap kegiatan menyemburkan awan panas, maka G. Merapi tergolong yang paling berbahaya di Indonesia.
Pada tanggal 8 September 1974, satu team yang berjumlah 5 orang terdiri dari dua orang Seksi Petapi, 2 orang dari Labolatorium Kimia Mineral dan 1 orang lagi di Cabang Dinas Volkanologi Yogyakarta telah mengadakan pendakian ke puncak kawah Gunung Merapi di Jawa Tengah.
Perjalanan ke G. Merapi (Plawangan - Babadan) dilakukan selama 20 hari terhitung dari tanggal 26 Maret - 14 April 1959.
Berita interlokal tgl 25 Djuni 1957 dari Pusat Pendjagaan Merapi di Djokja kepada Pusat Djawatan Geologi di Bandung, melaporkan bahwa, G. Merapi tambah giat. Guguran - guguran benda - benda berapi dari puntjak Trising terus - menerus, turun ke Sektor Trising- Senowo.
Termasuk lanjutan pemintaan Kep. U.G.A Jogyakarta tgl 11 Mei 1954 No. 249/60/UGA/M/54 dan dengan surat perintah Kep. Djawatan Pertambangan Tjb. Jogjakarta tgl 17 Juli 1954 No. 116/Um, penulis mengerjakan Trianguleren di Pos U.G.A Krindjing.
Sehubungan dengan surat tugas No. 125/Um. tgl 28/8-1954 dari Kepala Cabang Djawatan Pertambangan Yogyakarta, beserta Sdr. Merkum maka kami mulai menyelenggarakan bunyi pasal 2 (Mengadakan peilingen ke bagian - bagian dari puncak), dari surat No. 249/60/UGA/M/54 tertanggal 11 Mei 1954 oleh Kepala U.G.A Yogyakarta.
The summit of G. Merapi is formed by a lava-plug; a cratershaped decline, such as the most volcanoes possess, is not present. However it is known,-thanks to the many interest, with which the G. Herapi in the pant century obtained, that the volcano in another stage of eruptive activity certainly owed such a cratershaped decline.
As already earlier mentioned the G. Herapi exists of two morphologic clearly to be distinguished parts, an older eastern and a younger western part. From the sunnit of the old ringdike, only a small part remains (see portrait 14), of which the eastern part is named G. Pusunglondon (2694.3 a.s.) and the northern G. Paseban (2679= a.s.). The old volcano mantle of the G. Merapi has grown much more…
On October 12, 1920 the inhabitants of the most high laying kampungs in the vicinity of the Blongkengravine were surprised by hot dustclouds and were killed by the burns. It appeared inmediately, that there was no outburst at all, as the summit slopes of the Merapi were, as far as they were overgrown in August and September, were still green as before (the reports from news papers concerning th…