CVGHM raised the Alert Level for Lokon-Empung from 2 to 3 (on a scale of 1-4) on 9 December based on visual observations, inflation detected by deformation instruments, and an increase in seismicity. The water in the Tompaluan crater changed color from green to gray and noises from degassing became stronger. White plumes rose from the crater to an altitude of 1.6 km (5,200 ft) a.s.l. Visitors and tourists were advised not to go within a 2-km radius of the crater.
Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM) – “Reports provided courtesy of the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.”
Volcano World : Supplement 