Report on Rinjani (Indonesia) — 5 May-11 May 2010
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 5 May-11 May 2010
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2010. Report on Rinjani (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 5 May-11 May 2010. Smithsonian Institution and US Geological Survey.
8.42°S, 116.47°E; summit elev. 3726 m
All times are local (unless otherwise noted)
Based on analysis of satellite imagery, the Darwin VAAC reported that on 5 May a possible ash plume from Rinjani rose to an altitude of 5.5 km (18,000 ft) a.s.l. and drifted 150 km NW. The plume was not seen in imagery about six hours later. CVGHM advised the VAAC that intermittent activity could produce ash plumes to 1.5 km (5,000 ft) above the caldera.
Geologic Background. Rinjani volcano on the island of Lombok rises to 3726 m, second in height among Indonesian volcanoes only to Sumatra's Kerinci volcano. Rinjani has a steep-sided conical profile when viewed from the east, but the west side of the compound volcano is truncated by the 6 x 8.5 km, oval-shaped Segara Anak (Samalas) caldera. The caldera formed during one of the largest Holocene eruptions globally in 1257 CE, which truncated Samalas stratovolcano. The western half of the caldera contains a 230-m-deep lake whose crescentic form results from growth of the post-caldera cone Barujari at the east end of the caldera. Historical eruptions dating back to 1847 have been restricted to Barujari cone and consist of moderate explosive activity and occasional lava flows that have entered Segara Anak lake.