Continuing its pattern of heightened activity, Mount Redoubt released a plume of ash, volcanic gases, and steam on April 1, 2009, according to the Alaska Volcano Observatory. Although most emissions remained below an altitude of 4,572 meters (15,000 feet), the plume occasionally reached a height of 7,620 meters (25,000 feet) above sea level.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite took this picture the same day. In this image, the plume from Mount Redoubt appears as a translucent beige-gray swath that fans out slightly as it blows across Cook Inlet toward the east-southeast. North of the plume, volcanic ash from recent eruptions has given a gray-brown hue to what was previously a snowy white surface.
After keeping volcanologists waiting for weeks, Mount Redoubt erupted five times in one night, beginning on March 22, 2009. The volcano followed up with more eruptions in April, and showed continued signs of unrest in early May.