On March 8, 2005, Mount St Helens belched a large cloud of ash and steam, the largest to erupt from the volcano since October 2004. The volcano rumbled back to life in September 2004, and has been restless ever since. The IKONOS satellite snapped the top image of Mount St Helens on March 9, the day after the most recent eruption. In the five months between October 4, when Ikonos acquired the bottom image, and March 9, a new lava dome has grown in the crater. The new dome forms a large brown bulge that wasn’t previously present. The USGS Cascades Volcano Observatory reports that the dome had risen 500 feet above the top of the old lava dome as of February 1, 2005. The top of the dome is about 700 feet below the rim of the crater, the circular ridge below the dome. Another feature that points to Mount St. Helens’ recent activity is the snow inside the crater, which is tinted brown with ash. Other differences between March 9 and October 4 may be a result of the time of day—shadows fall in different places in the images because of the sun’s location when each image was acquired.
This image originally appeared on the Earth Observatory. Click here to view the full, original record.