By mid-August, Sakurajima Volcano—one of Japan’s most active—had erupted ash at least once every week during 2010. On August 19, 2010, an ash plume was sighted at 9,000 feet (2,700 meters), according to the Tokyo Volcanic Ash Advisory Center. This natural-color satellite image shows the gray plume moving west (towards image top) from the volcano’s summit. Simultaneously, a pyroclastic flow descended the eastern slopes.
Although Sakurajima’s activity since 1955 has been characterized by frequent small eruptions, the volcano still poses a danger to the densely-populated surroundings. Roughly 7,000 years ago Sakurajima erupted with a volcanic explosivity index (VEI) of 6, equivalent to the 1991 eruption of Mount Pinatubo.
The image was acquired by the Advanced Land Imager (ALI) aboard the Earth Observing-1 (EO-1) satellite.
NASA Earth Observatory image by Robert Simmon, using ALI data from the NASA EO-1 team. Caption by Robert Simmon.
Satellite view of an ash plume and pyroclastic flow on Sakurajima Volcano.
In contrast to the explosive eruptions of the previous week, ash emissions from Mount Redoubt became more frequent but confined to lower altitudes on March 30, 2009. The commercial satellite GeoEye-1 captured a high-resolution view of the volcano the same day.