The recent clear weather has allowed scientists at MVO to observe several incandescent areas on the lava dome.
The photograph shown was taken at 11 pm on 11 November during an exceptionally clear period. It clearly shows that, although it has been nine months since lava extrusion stopped, some areas of the dome are still hot enough to produce incandescence visible to the naked eye (not all the glowing areas on the photograph are visible to the naked eye). Many of the point sources seen in the image are related to fumaroles issuing from fractures that may penetrate into the lava dome. Calculations indicate that the dome could be at 720 degrees celsius 10 meters below the surface nine months after lava extrusion has ceased. Therefore areas from which recent rockfalls and pyroclastic flows have taken place would reveal this hotter interior and this is quite likely to be incandescent at night. The incandescence from surface features on the dome indicates that hot magmatic gases originating from a deeper source are likely to be maintaining the high temperatures. This demonstrates that the volcano has not "shut down" and that further lava extrusion is a real possibility.
MVO uses both thermal infra-red and visual images to monitor the fumaroles and incandescence for any changes that may indicate continued cooling or potential signs of a restart of lava extrusion.