Constraints on the size, overpressure, and volatile content of the Mount St. Helens magma system from geodetic and dome-growth measurements during the 2004-2006+ eruption

During the ongoing eruption at Mount St. Helens, Washington, lava has extruded continuously at a rate that decreased from ~7-9 m³ /s in October 2004 to 1-2 m³ /s by December 2005. The volume loss in the magma reservoir estimated from the geodetic data, 1.6-2.7×10 ⁷ m3 , is only a few tens of percent of the 7.5×10 7 m³ volume that had erupted by the end of 2005.