Rabaul Volcano continued smoking on August 9, 2009, as the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite passed overhead. The same day that MODIS acquired this true-color image of the volcano, the U.S. Air Force Weather Agency reported an ash plume extending roughly 56 kilometers (30 nautical miles) northeast of the summit.
The volcanic plume’s white color suggests that it likely contains more water vapor than volcanic ash. Streaks of white near the plume might be remnants from earlier emissions. Despite its predominantly white color, the volcanic plume has less distinct margins than local bright, opaque clouds. West of the volcano, pale patches appear off the northern coast of New Britain. These light-colored areas probably result from sunglint—sunlight bouncing off the ocean surface and into the satellite sensor.
Rabaul is a pyroclastic shield volcano with a low, broad profile. In 1994, the volcano erupted explosively enough to force the evacuation of Rabaul City. Prior to that eruption, the volcano had formed a natural harbor for the city.