Images

USGS topographers making an electronic distance measurement in a dry lake bed in Saline Valley in Death Valley, California.

USGS topographer using a Topcon Guppy in the dunes of Saline Valley in Death Valley, California

USGS topographer identifying a mine on a photograph in Death Valley.

USGS topographer running a traverse in the Alabama Hills near Mt. Whitney, California.

USGS topographer with plane table and alidade in the Alabama Hills near Mt. Whitney, California.

USGS topographers doing a helicopter photo reconnaissance in Saline Valley in Death Valley, California.

Debris avalanche deposit with hummocky terrain resulting from the May 18, 1980 eruption of Mount St. Helens. View to the east toward Coldwater Lake.

By 1987, the dome had replaced only three percent of the volume removed by the May 18, 1980 eruption. If that rate of growth had continued it would have taken over 200 years to rebuild Mount St. Helens to its pre-1980 size. Instead, Mount St. Helens entered a quiet period which continued until 2004.

The April 1983 landslide at Thistle, Utah, created a 200-ft-high (60-m-high) blockage of Spanish Fork canyon that caused disastrous flooding of the Thistle creek and Soldier Creek valleys upstream.  The flooding caused by the landslide required relocation of a major highway and railway.  An emergency spillway and diversion tunnels were constructed to drain

Lava fountains erupt from fissures during the first week of the Pu‘u ‘Ō‘ō eruption south of Pu‘u Kahaualea, approximately 2.4 km (1.5 miles) northeast of where subsequent eruptions built the Pu‘u ‘Ō‘ō cone. The early fissures cut through old forested lava flows in a remote section of Kīlauea's east rift zone.

One major concern to people living downstream of Mount St. Helens was a breakout of any of the impounded lakes, such as Coldwater or Castle Lakes, due to the instability of the debris dams blocking them. Flood waters from a breakout could be more catastrophic than the lahars of May 18, 1980.

View of Mt. St. Helens during minor eruption, two years after the major eruption on May 18, 1980.

Plume rises from Mount St. Helens' dome, Spirit Lake in foreground; view from the north. May 19, 1982.

Glacier extent maps on Mount St. Helens from before and after the May 18, 1980 eruption.

Outlet channels were built at Castle Lake and Coldwater Lake (shown here) to stabilize water levels and prevent overtopping of the debris dams.

USGS geologists gathered samples by hand from vents on the dome and crater floor. Additionally, sulfur dioxide gas was measured from a specially equipped airplane before, during, and after eruptions to determine "emission rates" for the volcano.

USGS geologists gathered samples by hand from vents on the dome and crater floor. Additionally, sulfur dioxide gas was measured from a specially-equipped airplane before, during, and after eruptions to determine "emission rates" for the volcano. During eruptions, emission rates typically increased to 5 to 10 times their pre-eruptive value.

In this view the dome is 535 feet (163 meters) high and nearly 1/4 mile (0.4 kilometers) wide, making it taller than a 44-story building (or, nearly the height of the Washington Monument) and wider than the length of four football fields. Compare with image taken August 12, 1985 from the same location with the same camera.

Seismic station installation in Mount St. Helens's crater 1981 lava dome. USGS, in conjunction with the University of Washington, maintain seismic stations at Mount St. Helens. An increase in seismicity (earthquakes) is often the first precursor to an approaching eruption.

The U.S. Geological Survey, in conjunction with the University of Washington, maintain seismic stations at Mount St. Helens. An increase in seismicity (earthquakes) is often the first precursor to an approaching eruption.

Pinnacles left by erosion of fumaroles that formed as layered pyroclastic flow deposit released gas and solidified into chimneys that eventually eroded, Crater Lake, Oregon.