| Mount St. Helens has erupted more frequently than any other volcano in the Cascade Range during the past 4,000 years. The volcano has exhibited a variety of eruption styles--explosive eruptions of pumice and ash, slow but continuous extrusions of viscous lava, and eruptions of fluid lava. Evidence of the volcano's older eruptions is recorded in the rocks that build and the deposits that flank the mountain. Eruptions at Mount St. Helens over the past three decades serve as reminders of the powerful geologic forces that are reshaping the landscape of the Pacific Northwest. -- Ramsey, et.al., 2008 |
