Rabaul Volcano, on the northeastern tip of Papua New Guinea’s island of New Britain released a plume of ash and steam on November 20, 2008. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite took this picture the same day. In this image, a dingy gray plume blows westward over the Bismarck Sea from the volcano’s summit. The plume differs from the nearby clouds in both its darker color and more diffuse shape.
Rabaul is a pyroclastic shield volcano formed from volcanic ash, rock fragments, and other material left behind by former volcanic eruptions. The volcano’s low profile resembles an ancient warrior shield, although this volcano has an asymmetrical shape. Before its major eruption in 1994, which forced residents of Rabaul City to evacuate, the volcano had been used as a natural harbor.