Report on Sorikmarapi (Indonesia) — August 1987
Scientific Event Alert Network Bulletin, vol. 12, no. 8 (August 1987)
Managing Editor: Lindsay McClelland.
Sorikmarapi (Indonesia) Seismicity and fumarole temperatures increase
Please cite this report as:
Global Volcanism Program, 1987. Report on Sorikmarapi (Indonesia). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 12:8. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198708-261120.
0.686°N, 99.539°E; summit elev. 2145 m
All times are local (unless otherwise noted)
Temperatures increased at two fumaroles during August: from 104 to 197°C at the N crater, and from 95 to 108°C at Sibangor Julu. White fume was almost continuously present, rising to ~100 m above the crater. In late August, seismic activity began to increase. By early September, near-surface earthquakes averaged ~7/day and deeper, tectonic earthquakes averaged ~40/day.
Geologic Background. Sorikmarapi is a forested stratovolcano with a 600-m-wide summit crater containing a 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.
Information Contacts: VSI.