These are preliminary observations of GMS imagery of the Rabaul Caldera eruption. All times are in Greenich Mean Time.

18 Sept 2130 No eruption cloud visible
18 Sept 2230 Eruption cloud visible, V-shaped cloud with limbs to the NW and SW
18 Sept 2300 Cloud growing, moving west, and dispersing to the NW and SW
18 Sept 2330 SW edge of cloud moving faster than NW edge, resulting in elongation to the SW
19 Sept 0030 Possible shock wave visible in cloud structure
19 Sept 0930 SW edge of cloud now moving back towards the east
19 Sept 1530 Eruption intensity appears to have diminished
19 Sept 1700 First of three (?) pulses of more energetic activity
19 Sept 1730 Pulse moving towards the NW
19 Sept 1830 "V-shaped" cloud structure greatly diminished
19 Sept 2130 Second Pulse, smaller than the first one
19 Sept 2230 First and second pulse moving towards the NW
20 Sept 0130 Third Pulse, smallest one of the three
20 Sept 0230 Start of continuous, "pencil-like" plume, disersing towards the SW
20 Sept 0430 Decline in size of plume in each successive image
20 Sept 0930 Plume structure very small to non-exsistant
20 Sept 1630 Plume hard to distinguish as meteorlogical clouds move in from the east

Compiled by Dave Schneider