Images

The east face of Middle Sister is 350 m (1150 ft) high. Ice-sculpted pile of lavas at right, variously called "Black Hump," "Prouty Point," or "Step Sister," has 190 m of relief and consists of at least five flows.

Mount St. Helens and the industrial waterfront area of North Portland, Oregon along the Willamette River in the foreground. Excess sediment from volcanoes can significantly impact river traffic.

The May 18, 1980 eruption of Mount St. Helens had a dramatic impact on the North Fork Toutle River. The debris avalanche, lateral blast and ashfall produced a substantial amount of sediment, which continues to be washed into the river and transported downstream.

Logs float in Spirit Lake near the Spirit Lake gaging station and outflow tunnel. View is to the south with Mount St. Helens in the background.

The USGS, in collaboration with UNAVCO and the University of Colorado, uses these data to measure channel erosion and deposition in the reach.

USGS geologist uses a UV spectrometer to detect gases from fumarole at Crater Rock, Mount Hood.

Back at the USGS Cascades Volcano Observatory office, these data are merged with airborne LiDAR data to calculate lake volume.

Volcano monitoring stations must be designed to withstand harsh winter conditions.

Extending approximately 75 miles north to south and 27 miles east to west, Newberry Volcano and its broad apron of lavas (light yellow shaded area) cover a total area of almost 1,200 square miles, making it the largest volcano of the Cascades volcanic chain. Its lavas stretch north beyond Smith Rock State Park, and south almost to Fort Rock State Natural Area.

Mount Rainier rises above Tacoma, Washington and boat harbor, which may be impacted during the next eruption of the volcano.

Stream channel cross-section measurements—instrument that uses laser pulses to survey distance to a reflector operated by a second crew member, Mount St. Helens.

Global Positioning System receiver (called a GPS monument) at North Rim Station, a monitoring location at Newberry volcano, Oregon.

View looking south across Newberry caldera towards the Big Obsidian flow (left of center) and Paulina Peak, with Paulina Lake in foreground. Photo taken from the north rim of the caldera.

Gas sampling with a CO2 Infrared Spectrometer at Mount St. Helens' September Lobe lava dome, Washington.

View of Mt. St. Helens at sunset, taken sometime after the crater forming eruption in 1980.

A view looking northeast across the central caldera of Newberry Volcano.  Paulina Lake is in the foreground and East Lake is in the distance.  The Central Pumice Cone lies between the two lakes. Near the bottom of the photo at the south edge of Paulina Lake, the two hills are named the Lakeshore Domes.

Mount Baker's northeastern face, Washington.

Suspended sediment sample collection from the North Fork Toutle River above the Sediment Retention Structure, downstream from Mount St. Helens.

Mount St. Helens, as viewed from Coldwater Ridge around sunset.

Seismic station VALT in Mount St. Helens crater, view toward the south.

The USGS operates a real-time lake elevation monitoring gage on Spirit Lake to ensure water level does not exceed a safe limit. In 1985, the U.S.