Images

Apollinaris Spring in 1987.  The spring was modified in 1925 so that water would flow through pipes to be emitted from a rock wall.  Yellowstone National Park photo by Jim Peaco.

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.

Morning Glory Pool used to be clear blue in color, as shown in the historic undated photo on the left (National Park Service photo by Rentchler).

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.

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.

Generalized geologic map of the Eocene Absaroka volcanic field (modified from Smedes and Prostka, 1972 and “Geology of Wyoming”).

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.

Seismic geyser in eruption in 1970.

Silicified logs of Queen's Laundry bathhouse

Seismic geyser in Yellowstone’s Upper Geyser Basin during an eruption. Based on the study of George Marler and USGS scientist Donald E.

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).

Kaleidoscope Geyser in the Lower Geyser Basin. George D. Marler and Donald E.

Seismic Geyser on the east bank of the Firehole River in the Upper Geyser Basin.

This orthophoto of Pocket Basin, a hydrothermal explosion crater in Yellowstone National Park's Lower Geyser Basin, was created from aerial photos taken in 1965 that were corrected to have uniform scale for use in geologic mapping.

President Kennedy signs the nuclear test ban treaty for the United States in 1963. Photo from National Archives, Still Pictures Division, Department of State Collection 59-0, box 23 (https://nsarchive2.gwu.edu/NSAEBB/NSAEBB94/tb02.htm).

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.