Images

View looking west of Mount St. Helens' summit after several small explosive eruptions. The smaller of the two pit craters was formed first on March 27. Subsequent eruptions opened the farther crater.

Ash covered snow is a result of wind direction, resulting in left portion of cone free of ash while the right portion is covered. Snowstorms later covered these ash layers, which in turn were covered by new ash. The result was many alternating layers of snow and ash.

An east-west fault across middle of summit area and an uplift or bulge on upper north flank of the volcano are also visible in this photo.

View from the north of Mount St. Helens' eruption and first crater.

Although seismic activity began under Mount St. Helens on March 20, this overflight showed no unusual features except numerous tracks of earthquake-triggered snow avalanches. No evidence of fracturing of summit area was detected during careful visual observations on the afternoon of March 24, 1980.

Before the devastating May 18, 1980 eruption, Mount St. Helens was considered to be one of the most beautiful and most frequently-climbed peaks in the Cascade Range. Spirit Lake was a vacation area offering hiking, camping, boating, and fishing.

Summit region (Kalama age–1479 to 1720 C.E.) of Mount St. Helens looking northeast. Spirit Lake and Mount Adams in background. September 28, 1979.

Before the eruption of May 18, 1980, Mount St. Helens' elevation was 2,950 m (9,677 ft). View from the west, Mount Adams in distance. S. Fork Toutle River is valley in center of photo.

Mount Adams elevation is 3,745 m (12, 286 ft). Mount St. Helens was the smallest of five major volcanic peaks in Washington State.

Worm Complex on the southeast flank of Mount St. Helens—Middle Kalama lava flows in center of image. Photo from September 28, 1979. Click to view larger image.

Studebaker Ridge formed during the Tertiary geologic time period (65 million to 2.6 million years ago). The pyroclastic surge from the May 18, 1980 eruption destroyed the trees on the ridge.

Shoestring Glacier on Mount St. Helens, viewed from the southeast. Photo from May, 1965.

Aerial photo of Mount St. Helens taken from the northeast in September 1964.  

Researchers map the bottom of Castle Lake, near Mount St. Helens. For three days, researchers ran a small boat over the lake surface equipped with an acoustic Doppler current profiler (ADCP). The ADCP bounces an acoustic wave off the bottom that is reflected back to a mobile receiver in the boat.

Remnant of Villard Glacier is in cirque below. Thick summit lava flow makes up "Glisan Pinnacle," which overlies hundreds of thin rubbly lava flows that are intercalated with red-oxidized agglutinate and scoria falls exposed on 800-m- (2600-ft-) high face below. Flows that form ridge at upper right are thicker than those on most of edifice.

Three Sisters annotated photograph viewed from south to North from Broken Top, Oregon.

Dome building episode from 2004-2008 at Mount St. Helens can be observed and measured with these two digital elevation models (DEMs) developed before and after the eruptive episode.

Tiltmeters allowed 24-hour monitoring as the information was telemetered back to CVO. Other instruments such as displacement meters for measuring cracks, seismometers for measuring earthquakes, gas sensors for measuring gas concentrations, and magnetometers for measuring the magnetic field, were also used for 24-hour monitoring.

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.

Information regarding volume and rates of advance for the crevassed Crater Glacier at Mount St. Helens, Washington, are extracted from Digital Elevation Models created from aerial photography. The red line shows the extent of Crater Glacier in 2012. Since 2012, the glacier has advanced about 50 m (160 ft) down the Loowit channel.

Erratics located on a cinder cone on the northeast flank of Newberry Volcano, Oregon.

Mount St. Helens prior to the catastrophic eruption of May 18, 1980. Streams and lava flows also visible. View is looking southerly from oblique aerial view. Mount Hood in distance.