Images

Wyoming StreamStats basin delineation at Green River below Fontenelle Reservoir

This site was burned but not invaded by exotic annual grasses. Many perennial bunchgrasses were present before the fire and were able to recover quickly afterwards.

Cheatgrass has invaded the space between sagebrush shrubs on this landscape south of Rock Springs in Wyoming. 

This landscape south of Rock Springs, Wyoming was burned and subsequently invaded by cheatgrass. Cheatgrass has a short growing season and leaves behind mats of dry, dead material that serves as wildfire fuel--contributing to a cycle of more frequent and larger wildfires and more plant invasions.

This site south of Rock Springs in Wyoming was not burned but cheatgrass has invaded the space between sagebrush shrubs. 

High-resolution satellite images of the Porcelain Basin and Nuphar Lake areas of Norris Geyser Basin acquired by Quickbird-2 on September 11, 2006 and WorldView-3 on March 30, 2022.  Note the change in color of Nuphar lake, from deep green to light blue, over time, as well as the increased evidence of flow from thermal features on the east side of Porcelain Bas

Map of Yellowstone region showing the backbone (triangles) and dense 2020 (yellow squares) seismic networks, and based on Wu et al. (2023).

Four examples of vertical ground shaking during Steamboat Geyser eruptions as recorded by seismic station YNM. The vertical scale is the same for each seismogram.

Map of Norris Geyser Basin showing the locations of major subbasins, roads and trails, and Nuphar Lake.

Comparison between the velocity structures outlining the Yellowstone’s upper-crustal magma reservoir at 5 km (3 mi) depth based on sparse (left) and dense (right) seismic networks. The open squares denote the locations of seismic sensors. Warmer color indicates lower velocity, representing higher melt fraction within the medium.

Visible (top) and thermal (bottom) images of Porcelain Basin looking to the north from the old roadbed.  Nuphar Lake is off the photograph to the right.  Cool-water seeps into Porcelain Basin are clearly evident in the thermal image and appear to flow underground from Nuphar Lake.  USGS photos by Mike Poland, July 1, 2023.

This site south of Rock Springs in Wyoming represents an intact sagebrush ecosystem. It has not been burned or invaded by exotic annual grasses. Undisturbed sagebrush steppe has bare ground between shrubs which helps to limit the spread of wildfire. When cheatgrass invades fires can grow larger.

High-resolution satellite images of the Porcelain Basin and Nuphar Lake areas of Norris Geyser Basin acquired by Quickbird-2 on September 11, 2006 (left), WorldView-3 on July 7, 2016 (middle), and WorldView-3 on March 30, 2022 (right).  Note the change in color of Nuphar lake, from deep green to light blue, over time, as well as the increased evidence of flow f

Schematic model of Yellowstone’s subsurface magmatic sill complex based on seismic data collected in 2020.

Map of Geyser Hill, Upper Geyser Basin, Yellowstone National Park, showing selected thermal features, including new and reactivated features that were active during the May-June 2023 thermal unrest.  Map prepared by by Kiernan Folz-Donahue, Yellowstone National Park.

A garter snake along Violet Creek near the Mary Mountain Trail in Hayden Valley, Yellowstone National Park. This snake used the geothermally warmed creek to thermoregulate during near-freezing overnight conditions. USGS photo by Stanley Mordensky, June 2023.

Hydrothermal explosion crater that has existed since at least 1954 located just southwest of The Gap in Norris Geyser Basin, Yellowstone National Park. Photo taken in June 2023 by Lauren Harrison.

Map of continuous Global Positioning System (GPS), semipermanent GPS, borehole strainmeters, and borehole tiltmeters that provide surface deformation monitoring capability in and around Yellowstone National Park. Red line denotes boundary of Yellowstone Caldera.

A garter snake along Violet Creek near the Mary Mountain Trail in Hayden Valley, Yellowstone National Park. This snake used the geothermally warmed creek to thermoregulate during near-freezing overnight conditions. USGS photo by Stanley Mordensky, June 2023.

Thermal feature UNNG-GHG-17a, not far from Sponge Geyser on Geyser Hill in Upper Geyser Basin, Yellowstone National Park.  The feature formed during a period of thermal unrest that began in May 2023 and threw debris and hot water onto the adjacent boardwalk, which was closed for safety.  National Park Service photo by Kiernan Folz-Donahue, May 31, 2023.

Distribution of hydrothermal features in Yellowstone as a function of their pH (modified and updated from Nordstrom et al., 2009). There are two distinct groupings: one is more acidic, and the other neutral to basic.