Krakatau catastrophic eruption in 1883 produced a large amount of pumice in the form of pyroclastic flow or fall. At present, they are on Rakata, Sertung, Panjang, and Sebesi islands. The pumice as the major constituent, often accompanied by obsidian is petrographically and chemically analysed. Most pumice was white with some pink and blackish grey; in various from ash, sand lapilli to block. M…
In Anak Krakatau's fifty years of existence an evolutionary developmental growth of its geomorphology and a gradually changing silica-content in the effusive throughout its five decades of eruptive activity could be recognied (De Neve, 1980, 1981).
A program to carry out a series of integrated research activities on Mount Krakatau and the surrounding area has been drawn up and circulated to relevant parties by the Indonesian is planned to span for two years, beginning in Augst 1981.
Krakatau was studied from September 10 - 12. The 1883 eruption produced a large non - walded ignimbrite deposit (ash - flow) which covers large areas of Rakata, Sertung and Rakata Islands. We landed on all three islands at accesible points and axamined coastal exposures of the 1883 deposit.
Sesuai rencana kerja proyek pemetaan geologi Gunungapi Sub-Direktorat Pemetaan Gunungapi Direktorat Vulkanologi pada PELITA III geologi gunungapi Krakatau. Pekerjaan lapangan berlangsung 40 hari dari 13 Maret sampai dengan 21 April 1982.
Menurut M. Neumann Van Padang (1951, H. 7) Merupakan kerucut gunungapi pada lereng selatan G. Geureudong, pada jarak 4 1/2 m dari puncaknya, meninggalkan sisa - sisa lama dari tepi - tepi kawah A, B dan, C.
Mount Lamongan, 1670 m above sea level, is located in the regencies of Lumajang and Probolinggo, East Java. Geographically it lies between latitudes 7'46'23' to 8'8'3' South and longitudes 113' 13'20' tto 113'23' East. It covers the area of about 1000 square kilometers.
Sigi kelandaian lereng sekitar G. Tangkuban Parahu dimaksudkan untuk memonitor kegiata tersebut dihubungkan dengan perubahan harga kelandaian lereng yang dihasilkan dari pengukuran kelandaiannya.
Pada bulan Mai 1984, dilakukan sebuah pengukuran profil S.P. di puncak merapi pada jalur Gendol-Woro. Pengukuran ini melanjutkan penelitian yang telah dilakukan oleh Robach et al (1987).
Dalam tahun anggaran 1982/1983, Seksi Penginderaan Jauh Sub Direktorat Pemetaan Gunungapi, Direktorat Vulkanologi, akan melaksanakan pengecekan data geologi Gunung Salak, Jawa Barat berdasarkan tafsiran cira landsat dan potret udara.