On October 1, 2004, the first of several explosions on Mount St. Helens in Southwest Washington shot a plume of volcanic ash and gases into the atmosphere from a vent on the southwest margin of the growing welt. Four additional steam and ash explosions occurred through October 5, and three produced noticeable fallout of fine ash downwind.
Following the brief series of small steam-and-ash explosions, the volcano settled into a quieter phase of activity. On October 11, 2004, spines of solid, but still hot, lava punctured the surface of the deformed glacier, initiating a new dome-building phase of activity.
By late October, a larger whaleback-shaped extrusion of solid lava (called a spine) had emerged from the crater floor. During the 3 plus years of the eruption a series of hot, solid, smooth-sided lava spines rose from the vent, bulldozed their way across the crater floor, and piled up to form a new dome 460 m (1,500 ft) high.
For information: http://volcanoes.usgs.gov/volcanoes/st_helens/st_helens_geo_hist_100.html
ActiveLifestylesNW.com photo taken by Greg Johnson in LaCenter, Washington. To buy this photo, go to http://jppromotions.zenfolio.com/p401617757
