Halema'uma'u Ash Emission (August 20, 2008)

Beginning in early January 2008, sulfur dioxide emission rates from the summit area of Kilauea increased to 2 to 10 times above background values, prompting partial closure of the summit region by late February. On March 12, 2008, a new gas vent appeared low on the southeast wall of Halema'uma'u Crater (http://hvo.wr.usgs.gov/pressreleases/pr03_14_08.html). At 0258 on March 19, an explosive eruption occurred (http://hvo.wr.usgs.gov/pressreleases/pr03_19_08.html), opening and widening the gas vent slightly and scattering lithic lapilli and coarse ash over an area of about 50 hectares (124 acres). Several more explosive eruptions and dozens of ashy, brown-colored plumes have puncuated the otherwise gray-white gas plume since the initial vent opening (see http://hvo.wr.usgs.gov/kilauea/timeline/ for links to specific events). Though debatable, it is thought that most of these ashy plumes were caused by collapses of the vent walls. This video, from August 20, 2008, is a good example of what the ashy plumes look like, and clearly shows the collapse of a portion of the vent wall, on the eastern (left) side of the vent, preceding the emission of ash.

The images that comprise this video were acquired by a video monitoring system in the observation tower of the Hawaiian Volcano Observatory about 1.8 kilometers (1.1 miles) north of the vent. The original video acquisition rate was 5 frames per second, and the resulting video is played at 50 frames per second.