CVGHM reported that on 7 April the Alert Level for Egon was raised from 1 to 2 (on a scale of 1-4) due to a marked increase in seismic activity since 28 March. Small steam plumes normally rose 10 m above the crater.

Geological Summary. 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.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)