Images

Ngorongoro volcano, in Tanzania, east Africa, is a caldera that formed 2-3 million years ago.  The Ngorongoro Conservation Area is a UNESCO World Heritage Site and home to one of the densest concentrations of wildlife in Africa.  Satellite Image from CNES/Airbus via Google Earth.

Crested Pool, in Upper Geyser Basin near Castle Geyser.  Geyser Hill is in the background, and Old Faithful is the steaming feature at the upper right.  USGS photo by Mike Poland, October 12, 2020.

A 53,000-pound vibroseis truck, with a hydraulic vibration plate that creates signals like tiny earthquakes. The truck is parked at a roadside pullout near the Continental Divide in Yellowstone National Park.  Photo by Jamie Farrell, University of Utah, September 2020, taken under Yellowstone National Park research permit YELL-2020-SCI-8146.

View of dead lodgepole pine trees with “bobby socks” from having taken up hydrothermal water that contains dissolved silica and other minerals. Photo taken south of the Fountain Paint Pot Trail in Lower Geyser Basin, Yellowstone National Park, looking toward the southeast. USGS photo by Stanley Mordensky, August 28, 2020.

The current bridge across the Yellowstone River near Tower Junction.  The bridge was constructed in the early 1960s and has structural problems that require it to be replaced.  The bridge will be removed once the new Yellowstone River Bridge is completed (scheduled for 2026).  Photo by Jacob Frank (Yellowstone National Park) on August 17, 2020.

Sheep Mountain, in the Gallatin Range, as seen from the north along the Sky Rim Trail near Sunlight Creek (to the left is approximately east, and to the right is approximately west). Note the layered stratigraphy of the sedimentary rocks dipping to the west. USGS photo by Stanley Mordensky, August 2020.

Granite Peak (center) as seen from the north flank of Tempest Mountain. Note: The photographer did not approach this mountain goat. Instead, the mountain goat, which has likely learned to associate human behavior as a source of sodium (a common problem throughout the region), approached the photographer. USGS photo by Stanley Mordensky, August 2020.

View of Twin Peaks (left-most prominent peak), Mt. Hague (second-left-most prominent peak), and Mt.

Sapphire Pool, in Biscuit Basin, steams on a stormy morning. A few “biscuits” remain along the pool’s southern edge (center right of photo) – violent geyser eruptions destroyed hundreds of the features when the pool’s plumbing system changed after being jarred by the 1959 Hebgen Lake earthquake. National Park Service photo by Jacob W. Frank, July 20, 2020.

Photo of geologic units of the Absaroka volcanic province in northeastern Yellowstone National Park that shows volcaniclastic sandstones grading up into a conglomerate, followed by another sequence of sandstone to conglomerate. These repeating layers of the same-looking material make it difficult to assign them to a specific volcanic group.

Petrified trees on Specimen Ridge, Yellowstone National Park.  NPS photo by Jake Frank, June 13, 2020.

Two standing petrified (silicified) trees on Specimen Ridge in northeastern Yellowstone National Park. Photo by Jacob W. Frank, Yellowstone National Park (https://www.flickr.com/photos/yellowstonenps/50016729252).

Ground fissure along the shore of Stanley Lake, Idaho, cause by liquefaction during shaking from the March 31, 2020, Stanley earthquake. Photo by Zach Lifton, Idaho Geological Survey, May 2020.

Submerged trees at the inlet delta of Stanley Lake, Idaho. Liquefaction during shaking from the March 31, 2020, Stanley earthquake caused ground subsidence and collapse of the delta. Photo by Zach Lifton, Idaho Geological Survey, May 2020.

Map of USGS “Did You Feel It?” reports for the March 31, 2020, M6.5 Stanley, Idaho, earthquake.  Taken from https://earthquake.usgs.gov/earthquakes/eventpage/us70008jr5/dyfi/intensity.

Annie Carlson, Research Permitting Coordinator for Yellowstone National Park during 2017–2023, during a winter ski expedition in the park. National Park Service photo by Jon Nicholson, January 2020.

The Yellowstone River is divided into five reaches (labeled and color-coded): Yellowstone Lake, Hayden Valley, Grand Canyon of the Yellowstone, Tower–Gardner, and Mammoth.  Monitoring stations (yellow dots on map) between each reach of the river reaches allow geochemists to measure river composition and then determine the sources of chloride (Cl) and other solu

A digital elevation map of Yellowstone National Park (left) with the location of Yellowstone Lake indicated by the white box. Satellite image (right) of the study site with collection location of core YL16-2C shown by the red circle. Map was originally published in Sabrina Brown’s dissertation (2019).

An unnamed small acidic (pH ~3) hot spring (with a temperature of about 55°C at the source) in the Gibbon Geyser Basin of Yellowstone National Park. The yellow region is due to the precipitation of sulfur by sulfide-oxidizing chemotrophic microorganisms.

Several adult wetsalts tiger beetles hunting and basking on and around an alkaline hot spring near Midway Geyser Basin in Yellowstone National Park. Photo by Robert K. D. Peterson, 2019.

A wide array of phototrophic microbial community textures exhibited in an alkaline (pH ~8.5) hot spring outflow channel in the Biscuit Basin, including thick mats, toadstools, ropes, and pinnacles. The differences in color are due to pigments (chlorophylls, bacteriochlorophylls, and carotenoids) produced by phototrophic microorganisms.