Image source: GMS Infrared, 21 September 1999

Comments: This event is somewhat problematic, since it occurred during a period (17 September onwards) of enhanced activity at Tavurvur cone, but there is no record of a high level ash cloud during the event. The timing and location of the cloud suggests that this may be an example of a low level eruption triggering a thunderstorm over the volcano, which then disperses as a normal cumulonimbus cloud would, and would probably transport a little ash to much higher altitudes than would otherwise be the case.

References: Smithsonian Institution, Rabaul Volcano Observatory

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