Geologic Background:
Sorikmarapi is a forested stratovolcano with a
600-m-wide summit crater containing a crater lake and
substantial sulfur deposits. A smaller parasitic crater
(Danau Merah) on the upper SE flank also contains a
crater lake; these two craters and a series of smaller
explosion pits occur along a NW-SE line. Several
solfatara fields are located on the E flank. Phreatic
eruptions have occurred from summit and flank vents
during the 19th and 20th centuries.
Historic Activity:
- Eruptions in 1829, 1879, 1892, 1893, 1917, and
1970.
- A major eruption in 1892 produced lahars that killed
180 people in an E-flank village.
- Ash explosions occurred in 1917 and 1970,.
Recent Activity:
- Single explosion on July 5, 1986 with ash column 700
m above summit. Increased seismic activity in August and
September 1987.
Data Sources:
- Smithsonian's SEAN Bulletin (V. 11, No. 6 to V. 14,
No. 7).
- Global Volcanism Network (V. 21, No. 8)
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