In the early morning hours of September 23, 2004, a swarm of small-magnitude earthquakes about half a mile below Earth's surface marked the reawakening of Mount St. Helens. On October 1, 2004, the first of several small explosions shot a plume of volcanic ash and gases skyward. A growing welt beneath Crater Glacier heralded the rise of semi-solid magma that erupted onto the surface, forming rocky spines, smooth-sided ridges, and jumbled piles of lava over the next 34 months. During the eruption, scientists made important strides in volcano monitoring, developing new tools for investigation and insight into eruptive behavior. View the 2004-2008 Mount St. Helens Eruption video and read about the eruption in the 2004-2008 event timeline and statistics.
Since 2008, the Mount St. Helens Institute has brought live, interactive video presentations to students across the country. This fall, CVO scientists are featured:
USGS-CVO scientist Christoph Kern is co-author on a study that used ultraviolet spectral satellite data to quantify the exceptionally high sulfur dioxide (SO2) emissions from Kīlauea Volcano during the 2008 opening of the summit Overlook Crater. Kīlauea is particularly suited for quantitative investigations from satellite observations due to the large SO2 emission rates, absence of interfering gas emission sources, the clearly defined downwind plumes caused by steady trade winds and the generally low cloud cover downwind. This allowed the application of a new methodology in which monthly mean SO2 emission rates and effective SO2 lifetimes were derived simultaneously from the observed mean downwind plume evolution. Read Estimating the volcanic emission rate and atmospheric lifetime of SO2 from space: a case study for Kīlauea volcano, Hawai`i.