Grimsvotn in Iceland
This natural-color image was taken on May 21, 2011, by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite. "Lingering snow is visible beneath the clouds to the northeast (upper left). Brown ash covers a portion of the Vatnajokull Glacier near the Atlantic coast (lower right)," writes NASA. This eruption was not as powerful as the Eyjafjallajökull eruption in 2010, which notoriously disrupted international air travel for weeks. Grimsvotn is the most active volcano in Iceland as it is active in the center of a rift zone.