Images

La Garita Mountain (elevation 4179 m [13711 ft]), Colorado.  The mountain is a resurgent block of Fish Canyon Tuff that is more than 1 km (0.6 mi) thick—the top is eroded and the base is not exposed.  The tuff formed during the eruption of La Garita caldera about 27.8 million years ago and has a volume of more than 5000 km³ (1200 mi³)

Mount Vesuvius behind city of Naples. The modern cone of Vesuvius is flanked on the left by Monte Somma, the rim of a caldera that formed about 17,000 years ago. Eight major explosive eruptions have occurred since, including the 79 CE eruption that destroyed Pompeii and other towns.

Novarupta Dome, with Falling Mountain and the upper valley portion of the Valley of Ten Thousand Smokes in the background.  Photo by Tom Miller, June 1979.

USGS scientist Irving Friedman (1920–2005) was an adventure enthusiast. Here he is preparing for a dive with his longtime USGS colleague Peter Lipman at Makalawena Beach, north of Kailua-Kona on the Island of Hawai’i, in 1977. Photo by Peter Lipman.

Photo of damage to the Mammoth-Norris highway, just south of Mammoth Hot Springs, caused by the June 30, 1975, magnitude-6 earthquake.  Haynes Inc. photo for the Deseret News.

Muddy thermal discharge (foreground) near Congress Pool (middle ground) in Norris Geyser Basin following the June 30, 1975, magnitude-6 Yellowstone National Park earthquake,  NPS photo by Rick Hutchinson.

Gibbon River in Gibbon Meadows immediate following the June 30, 1975, magnitude-6 Yellowstone National Park earthquake.  The muddy color is due to increased sediment load.  NPS photo by Rick Hutchinson.

Map: Index map showing locations of 1967–1968 research drill holes in Yellowstone National Park. Taken from USGS Bulletin 1967.

An example Correlation of Map Units chart from the Surficial Geologic Map of Yellowstone National Park (U.S. Geological Survey, 1972) that demonstrates a typical classification scheme for surficial units.

Shoshone Tukudika (Sheepeater) men, women, and children at Medicine Lodge Creek, Idaho, in 1871. This photo was taken by U.S. Geological Survey employee William Henry Jackson.  Courtesy of National Park Service, Yellowstone National Park, YELL 8151.

Pearlette Ash in Comanche County, Kansas.  Kansas Geological Survey photo by Grace Muilenburg, April 1969 (https://chasm.kgs.ku.edu/ords/pubcat.phd2.View_Photo?f_id=3165).

Eruptions from drill rods during research drilling in Yellowstone National Park, 1967–1968. Left panel shows initial explosive eruption of water-steam mixture from open drill pipe in drill hole Y-5 (Rabbit Creek) on August 20, 1967.

Bob Fournier (left) and Don White (right) at the Y3 drilling site in Pocket Basin adjacent to Ojo Caliente, Lower Geyser Basin, Yellowstone National Park, in 1967.  USGS Photo.

The solubility of amorphous silica (solid silica with no crystal structure) in water as a function of temperature. When deep groundwater flows through hot rhyolite it can remove silica from the rhyolite (dissolve silica).

Top: the first thermal infrared images of Yellowstone (1961).  Warm areas are brighter; cold areas are darker.  These images were published in: McLerran, J.H. and Morgan, J.O. (1965) Thermal mapping of Yellowstone National Park.

Aerial view of Black Opal Pool, Black Diamond Pool, and part of Wall Pool, all in Biscuit Basin, Yellowstone National Park, taken in 1959 sometime after the Hebgen Lake earthquake (which occurred on August 17 of that year).

View of Lower Geyser Basin. Note active thermal pools (Great Fountain Geyser) in the foreground with thermal grasslands—kept treeless by hot soils—and lodgepole pine forest in the distance. Photo by George Marler, 1959.

Dragline work to lower the outlet channel of Earthquake Lake on October 18, 1959. The tripod on the hill at center left is one of five lighting plants that allowed nighttime work. Note the “bathtub ring” of killed trees along the shoreline marking the high stand of Earthquake Lake before lowering of the outlet channel. Photo by Mrs. Steven W. Nile (Dr.

View of the Madison Slide on August 21, 1959 with rapidly filling Earthquake Lake. Rock Creek Campground was near the flooded trees. Camping gear was left behind by survivors who sought high ground following the slide. Photo by Professor William B. Hall, Montana School of Mines Geology Department.

Irving Friedman (left) and William D. Long in 1958 carrying out experiments with welded volcanic tuffs at a USGS laboratory in Washington, D.C.

An ash plume rises from the summit crater of Parícutin sometime during 1946-48. A thick ash deposit covers the foreground. An estimated 4,500 cattle and 550 horses died during the heavy ashfall in the early months of the eruption, devastating the local people who depended on the animals for food, plowing, and transportation.