Images

East face of North Sister, 750 m high. Consists of about 100 thin mafic lava flows and intercalated layers of red scoria, capped by thick summit lava flows. Remnant of Thayer Glacier feeds cirque lake. Pervasively altered yellow-orange buttress on right, 250 m thick, consists of east-dipping, palagonitized, ash-rich fragmental flow deposits.

Prouty Glacier headwall on the northeast face of South Sister. Dipping stacks of lava and scoria were excavated by Prouty Glacier, exposing cross-sectional views of the last 33,000 years of summit activity. The 350-m-thick (11,500-ft) lava stacks are truncated at about 3000 m (9,800 ft) elevation, forming the ragged rim of a broad paleocrater.

Lost Creek Glacier and its cirque are in the center, and Eugene Glacier and its cirque are toward the bottom left. Fingerlike lobes of dacite lava dribble down northwest ridge atop fragmental deposit and beneath capping agglutinate. The entire edifice visible here was built between 30 and 20 ka.

The LUSI (Lumpur “mud”-Sidoarjo) mud volcano in East Java, Indonesia, has been erupting mud and gases since 2006. Eruption rates can be as high as 160,000 m³ per day, and the mud has displaced tens of thousands of people and caused billions of dollars in damage. USGS photo by Tom Casadevall, 2007.

Western edge of Sherman Crater in the foreground of the Mount Baker Summit, Washington, view slightly northwestward.

USGS scientist observing Mount St. Helens' crater and dome from the Brutus Camera station.

Mount Adams western profile as seen from Mount St. Helens.

Seismic station at Yellow Rock (YEL) with the toe of the west arm of Crater Glacier in the background. This station site was eventually covered by the glacier.

Panoramic photograph from the southern rim of Mount St. Helens' crater rim looking north with accompanying annotation.

View the annotated version of this photograph.

View the annotated image.

View northward from Mount St. Helens' crater rim, July 2006.

Helicopter flying toward lava spine at Mount St. Helens to collect rocks—note the "Jaws" collector hanging underneath. April 28, 2007

Due to the cataclysmic eruption of May 18, 1980, many of the locations annotated on this map are now either covered or no longer visible.

Crater Lake is the remnant of Mount Mazama, which erupted catastrophically 7,700 years ago to form the caldera.Wizard Island in lake and Mount Scott is peak on right shore. View from south. Oregon

Eruptions of the Yellowstone volcanic system have included the two largest volcanic eruptions in North America in the past few million years; the third largest was at Long Valley in California and produced the Bishop ash bed. The biggest of the Yellowstone eruptions occurred 2.1 million years ago, depositing the Huckleberry Ridge ash bed.

USGS Debris-flow flume near Blue River, Oregon is used to conduct debris flows and landslide experiments. Flume is a reinforced concrete channel 95 m (310 ft long, 2 m (6.6 ft) wide, and 1.2 m (4 ft).

Mount Adams, Washington as seen from Mount St. Helens (west). Trees are covered in frost in the foreground.

Loowit Falls flows north out of Mount St. Helens crater. White building in upper right corner is the Loowit gage house, which contains an Acoustic Flow Monitor.

South-facing aerial view of Mount St. Helens with Mount Hood (left) and Mount Jefferson (right) on the horizon. June 8, 2005.

Ash collection from east Crater Glacier on Mount St. Helens with a dredge attached to a helicopter cable. Ash is analyzed to help scientists understand eruption characteristics.