Images

Geology of the unconformity on Mount Everts in Yellowstone National Park.  Sketch at the top was made by geologist William Henry Holmes in 1878 and correctly identifies Cretaceous sediments overlain by much younger rhyolite rocks, including fine ash deposits (“tufa”).  The photo at the bottom shows the same outcrop as viewed from Mammoth Hot Springs (USGS

Pie diagram showing the chloride flux, in kilotons per year (kt/yr), measured in 2022, with percentages for the four major rivers (Madison, Yellowstone, Snake, and Falls rivers) that drain Yellowstone National Park. Figure developed by Baine McCleskey.

Images of an unnamed thermal feature in the Three River Junction thermal area in southwest Yellowstone National Park. A, WorldView-3 satellite image from September 2014. B, National Park Service (NPS) aerial photograph from 2017. Images A and B were acquired before the feature went largely dry in late 2019 or 2020. C, WorldView-3 satellite image from June 2020.

3D rendering of the shear-wave-speed anomaly (ɗVS) below Yellowstone. Regions of strongly reduced shear-wave speed most likely indicate volumes of partially molten crust. Iso-surfaces (surfaces of constant ɗVS) are shown in increments of 5%.

Seismic data coverage of the Yellowstone region and example of seismic noise records. By cross-correlating signals of the background noise recorded at two seismic stations and stacking the signals over many days, useful seismic waveforms can be extracted.

Map of seismicity (red circles) in the Yellowstone region during 2022. Gray lines are roads, black dashed line shows the caldera boundary, Yellowstone National Park is outlined by black dot-dashed line, and gray dashed lines denote state boundaries.

Google Earth image of the north part of Lower Geyser Basin showing the site of the Fountain Hotel and nearby Leather Pool, which was tapped to provide a source of hot water for the hotel.

Graph showing the discharge (blue) and specific conductance (black) measured at the Gardner River monitoring station in Yellowstone National Park during the June 10–13, 2022, flood.

Map of southern Idaho and the Snake River Plain, showing the eastern (ESRP) and western (WSRP) parts of the geologic province. Map by Zach Lifton, Idaho Geological Survey.

Jamie Farrell presents Yellowstone as one of the first 100 IUGS Geological Heritage Sites during the 60^th anniversary IUGS meeting in Zumaia, Spain in October, 2022.  Photo by Marjorie Chan.

Document certifying The Yellowstone Volcanic and Hydrothermal System, USA, as one of the first 100 IUGS Geological Heritage Sites as declared during the 60th anniversary IUGS meeting held in Zumaia, Spain in October 2022.

Interferogram created from data collected on September 29, 2021, and October 6, 2022, by the Sentinel-1 satellite system. Colored fringes indicate a change in distance (called range change) between the satellite and ground surface that is caused by surface deformation.

Atmospheric water vapor and river level measured during June 2022 in the northeast part of Yellowstone National Park. Gray line is the level of the Lamar River. Blue line is the amount of water vapor in the atmosphere above GPS station P720.

A cutbank exposure near West DuNoir Creek, Wyoming, illustrates the differences between bedrock and surficial geologic mapping. On bedrock maps this location is mapped as the Eocene (55–34 million years old) Indian Meadows Formation, which corresponds to the bedrock visible in the stream bed.

Photo of a newly eroded cliff along the Gardner River, Yellowstone National Park, showing the unconsolidated layers of sandstone and gravel. USGS photo by David Roth, September 5, 2022.

One method of rapidly cooling an experiment that involves molten rock. The volcanic material is dropped from inside the furnace (at ~1000 °C or 1830 °F!) down a vertical tube and into a bulb of room-temperature water.

Sediment cores from Twin Butte Lake, Yellowstone National Park, being analyzed in the laboratory.  (a) Photo of a freshly split core that exhibits a transition in lake productivity (grey sediment on bottom to dark organic rich sediment on top). One half of the core is scanned for multiple types of data and sampled while the other half of the core is archived.

Gardner River chloride flux monitoring site before and after the June 2022 flooding in Yellowstone National Park.  (Left) Site prior to June 2022 storm. Note that the riverbank is near to the base of the fallen tree. USGS photo by Blaine McCleskey, May 21, 2014.  (Right) Site after June 2022 storm. The probe is buried under ~4 feet of debris.

Landsat 8 thermal infrared images of Yellowstone showing daily and seasonal differences.  In these greyscale images, bright pixels are warmer and dark pixels are cooler.  In the daytime images (A and C), you can see the effects of topography, with darker (cooler) pixels like shadows on north-facing slopes and brighter (warmer) pixels on sun-facing slopes.&

Dr. Cathy Whitlock (Montana State University) in the “core description boat” on Twin Butte Lake, Yellowstone National Park, with a freshly extruded one meter (3 feet) sediment core. Cores are described and measured in the field before being carefully wrapped for transport to the lab. Photo taken under NPS research permit YELL-2022-SCI-0009 by S.

A string of pack mules led by the National Park Service packers Hannah Miller and Ben Cunningham carrying lake coring equipment to a small backcountry lake in Yellowstone National Park; photo taken under NPS research permit YELL-2022-SCI-0009 by S. Hurwitz in August 2022.