Report on Egon (Indonesia) — 8 September-14 September 2004
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 8 September-14 September 2004
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2004. Report on Egon (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 8 September-14 September 2004. Smithsonian Institution and US Geological Survey.
8.676°S, 122.455°E; summit elev. 1661 m
All times are local (unless otherwise noted)
A news article reported that an eruption at Egon on 13 September produced an ash plume that drifted ~70 km downwind according to an Indonesian volcanologist. No ash was visible on satellite imagery. There were no reports of injuries or deaths. About 2,200 villagers living on the volcano's slopes had been evacuated since July 2004. Many of the evacuees reported experiencing respiratory problems and skin irritation. The airport in the town of Maumere was closed due to up to 1 cm of ash deposited on facilities and equipment.
Geologic Background. Gunung Egon, also known as Namang, sits within the narrow section of eastern Flores Island. The barren, sparsely vegetated summit region has a 350-m-wide, 200-m-deep crater that sometimes contains a lake. Other small crater lakes occur on the flanks. A lava dome forms the southern summit. Solfataric activity occurs on the crater wall and rim and on the upper S flank. Reports of eruptive activity prior to explosive eruptions beginning in 2004 are unconfirmed. Emissions were often observed above the summit during 1888-1892. Strong emissions in 1907 reported by Sapper (1917) was considered by the Catalog of Active Volcanoes of the World (Neumann van Padang, 1951) to be an historical eruption, but Kemmerling (1929) noted that this was likely confused with an eruption on the same date and time from Lewotobi Lakilaki.