Images

The Sorlie Bridge between Grand Forks, North Dakota and East Grand Forks, Minnesota, during the 1997 Red River of the North flood.

U.S. Geological Survey employees being transported to sites by National Guard personnel.

Fire consumes an building on a farmstead near the Red River of the North in northeastern North Dakota.

Flood waters inundated Grand Forks, North Dakota and East Grand Forks, Minnesota.The picture is looking west to Grand Forks, North Dakota and the  USGS gage house is the small white square in the center of the picture.

The flag of the United States of American flies over flood water in Grand Forks, North Dakota.

Photograph of the large jökulhlaup that spread out across Skeiðarársandur (glacial outwash plain) from the terminus of Skeiðarárjökull, an outlet glacier of Vatnajökull.

A crystallized dacite flow in northern Chile. Dacite is extrusive and the volcanic equivalent of granodiorite. 

Channelized flows on Socompa. Socompa is a large stratovolcano on the border between Chile and Argentina, the youngest of a chain of volcanoes that runs northeast to southwest.

A burst tumulus near Kamokuna, which is a lava delta where Puʻu ʻŌʻō flows enter the Pacific Ocean. Tumuli can burst when the influx of lava is rapid compared to the rate at which the crust is thickening by cooling. In these cases the pressure driving the lava is significantly greater than the weight of the overlying crust.

Subsequent flows have fed lava into the skylight. A stationary crust is formed on margins of the flowing lava within the tube at this location, probably due to the loss of heat through the skylight.

A “drippy” tumulus near Kamokuna, which is a lava delta where Puʻu ʻŌʻō flows enter the Pacific Ocean. These tumuli form when the upwelling lava has a steady pressure and rate of movement, so the upper crust does not break apart. Instead, the lava slowly squeezes out.

A cinder cone within the Mount Aso caldera, located on Kyushu Island, Japan. The caldera contains several cinder cones and stratovolcanoes.

Rubens coil inside the Rock Magnetics Laboratory on the USGS Menlo Park campus. The function of the Rubens coil is to cancel the earth's magnetic field for thermal demagnetization of core samples. It is constructed of nonmagnetic materials and the control unit is place far enough away from the instrument to avoid interference from its metal components.

Flat-topped tumulus on Mauna Ulu lavas along Chain of Craters Road, Hawaii. Tumuli are just one end-member of a wide range of features formed by inflation of lava flows. A flat-topped tumulus is a half-way between a classic tumulus and a "lava-rise" or inflation plateau.

Flat-topped tumulus on Mauna Ulu lavas along Chain of Craters Road, Hawaii. Tumuli are just one end-member of a wide range of features formed by inflation of lava flows. A flat-topped tumulus is a half-way between a classic tumulus and a "lava-rise" or inflation plateau.

A classic marine tide pool environment among some of the black lava rocks found on the southern shore of Maui in the Hawaiian islands.

Rainstorm over Kauai mountains and Hanalei Bay at the North Shore of Kauai.

A classic marine tide pool environment among some of the black lava rocks found on the southern shore of Maui in the Hawaiian islands.

USGS scientists conduct research on the remote, rugged 'Alakai Plateau of Kaua'i.

Samples of welded scoria. Scoria is another word for the ‘cinders’ that make up volcanic cinder cones. Roza Member, Columbia River Basalt Group. Southeast of Winona, WA.

A detail of a pahoehoe lobe at the top of a tumulus. The upper crust that is lifted up during the formation of a tumulus is typically quite vesicular (has lots of bubbled trapped in it). Roza Formation, Columbia River Basalt Group. Southwest of Quincy, WA.