For three years, North Pagan Volcano has emitted intermittent volcanic plumes. Composed mainly of steam, the plumes also contained other volcanic gases (such as sulfur dioxide) and occasionally small amounts of ash. By mid 2011, Paganís activity was nearly continuous, and NASAís Moderate Resolution Imaging Spectroradiometer (MODIS), carried on both the Terra and Aqua satellites, detected a plume almost every time there was a clear view. (Satellites provide the only reliable observations of Pagan, as the island has been uninhabited since a major eruption forced residents to leave in 1981.)
This natural-color image of Pagan Island from May 7, 2012, was collected by the MODIS instrument on the Terra satellite. A volcanic plume blows westward from the summit of North Pagan Volcano. The plumeís blue tint suggests the presence of sulfur dioxide. Several hours after this image was acquired, the Ozone Monitoring Instrument (OMI) on the Aura satellite detected elevated levels of sulfur dioxide just west of the volcano.
Pagan Island is located in the arc of the islands which make up the Commonwealth of the Northern Mariana Islands (CNMI). The island contains two straovolcanoes which are connected by a narrow isthmus. Saipan, capital city, is located 173 nautical miles south of Pagan Island.