Rabaul Volcano on the island of New Britain released a plume on October 2, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite took this picture the same day. In this image, the volcanic plume of ash and/or steam is semi-transparent, dingy gray with indistinct outlines—in contrast to the opaque white clouds. The plume blows primarily westward over the northern portion of New Britain.
Rabaul is a pyroclastic shield volcano. Shield volcanoes resemble ancient warrior shields, thanks to their low, broad shape. Assembled from pyroclastic flows—avalanches of broken rocks, ash, and other volcanic materials—these volcanoes bear the traces of earlier eruptions. Rabaul rests on the northeastern end of New Britain. The volcano’s explosive 1994 eruption, occurring at the same time as eruptions of two neighboring volcanoes, forced the temporary evacuation of Rabaul City. Before that event, Rabaul City had used the sheltered harbor formed by the volcano.