Images

Plume within Mount St. Helens' crater, October 1, 2004 at 12:16 PDT.

Plume from Johnston Ridge Observatory, Mount St. Helens. October 1, 2004.

Mount St. Helens' crater, dome, and glacier uplift from the southeast, after steam and ash eruption.

Mount St. Helens' dome and glacier uplift from the east, after steam and ash eruption.

Mount St. Helens' dome and glacier uplift from the east, after steam and ash eruption.

Vent blasted through the Mount St. Helens' crater glacier.

South side of Mount St. Helens lava dome, as seen from the east, showing the dome and part of the glacier forming at the base of the dome. September 30, 2005

Western side of Mount St. Helens crater, and dome, showing the glacier forming at the base of the dome.

Close-in view of south side of Mount St. Helens lava dome, as seen from the southeast, showing the dome and part of the glacier forming at the base of the dome. September 2005

Mount St. Helens crater and dome as seen from SugarBowl, on the NE flank of the volcano. September 2005

Berm from a 1997 lahar is visible along the channel. Mount St. Helens' east crater wall is visible in the background.

South side of Mount St. Helens lava dome, as seen from the east, showing the dome and part of the glacier forming at the base of the dome. August 29, 2005

Sherman Crater (foreground) below the summit of Mount Baker, Washington.

Northeast crater wall above Sugar Bowl, Mount St. Helens with annotated deposits from some of the Spirit Lake Stage eruptive periods. Photograph from late summer 2003.

Mount Baker summit, Washington. Coleman Glacier to the left and Easton Glacier to the right. Lower peak on the right is the edge of Sherman Crater. View to east.

(Top) 1996–2000 interferogram draped over a 30-m DEM and showing uplift centered a few kilometers (miles) west of South Sister volcano. (Bottom) Geochemical data on top of the 1996–2000 interferogram. The columns show chloride (Cl) and sulfate (SO4) concentrations at sampled springs.

Potential volcanic hazards at Mount Baker.

Angle and distance measurements to the Mount St. Helens' flanks were taken periodically to monitor for deformation similar to the 1980 bulge. Station northeast of volcano.

Deformation measurements on the Mount St. Helens' dome; three geologists in middle bottom of this aerial photograph.

The last dome-building eruption of Mount St. Helens during the 1980s occurred in October 1986. A new lobe was extruded, increasing the dome's height to 925 feet (282 meters), making it taller than a 77-story building. In volume, the dome was nearly 40 times the size of Seattle's Kingdome stadium.

View of the Spirit Lake outlet tunnel, built in 1985, that allows water to drain out of Spirit Lake safely and maintain the lake's water level 100 ft (30 m) below the estimated overtopping level.