The Alaska Volcano Observatory utilizes satellite remote sensing to help monitor the 52 historically active volcanoes that comprise the 2,500-km-long Aleutian Arc. The primary volcanic hazard is to aviation along the busy North Pacific air routes. Remote sensing provides information that is used to detect, characterize, and monitor volcanic activity, particularly ash plumes, which can damage and clog jet engines.
Composite satellite image of Pavlof Volcano showing the extent of the lava flows on the northeastern flank. The base image was collected by the Worldview-2 satellite on May 9, 2014 (prior to the onset of eruptive activity) and is overlain (in color) with a Landsat 8 thermal infrared image collected on June 24, 2014. The thermal infrared sensor measured the heat given off by the still-warm lava flow. The length of the longest branch of the lava flow is about 5 km (3 miles). Note that the lava flow appears to have traveled under the ice on the upper flank of the volcano.