Images

Photos of flow breccia in Central Plateau Member rhyolites in Yellowstone National Park. A) Flow breccia observed in a drill core from the Lower Geyser Basin. The angular, light-colored clasts are fragments of the original lava carapace, broken and incorporated into the flow as it advanced. B) Flow breccia exposed in a road cut along Firehole Canyon Drive.

Seismic and infrasound data for the April 15, 2024, hydrothermal explosion on Porcelain Terrace at Norris Geyser Basin.  Top plot is seismic data from the YNM station, located at the Norris Geyser Basin Museum.  Middle plot is seismic data from station YNB, in the Ragged Hills of Norris Geyser Basin. Bottom plot is infrasound data from station YNB.&nb

Table showing different types of geochronology techniques, the ages over which those techniques are best applied, and the meaning of the ages determined by the techniques.

Plot showing the total geothermal radiant power output from Yellowstone’s thermal areas based on Landsat 8 and Landsat 9 thermal infrared images from 2014 to 2024.  Only data from clear, nighttime, wintertime (November through March) dates were used.  The results indicate that there has been no significant change over the last 10 years.

Plots showing the number of water samples collected over time (top) and by location (bottom) in the Yellowstone region since the late 1800s. Yellowstone’s archive of water-chemistry research data is a mosaic of scientific progress, built with the work of hundreds of people over more than a century and still growing today.

High-resolution satellite images of Norris Geyser Basin showing the area of Porcelain Basin and Nuphar Lake in April 2024.  In the left image, acquired on April 2, 2024, springs on Porcelain Terrace are full of water, and warm hydrothermal water is flowing into Nuphar Lake, keeping the north part of the lake free of ice.  Boardwalks in the area appear as w

History of travertine deposition in Yellowstone caldera and correlation with past climate conditions. a) The age of travertine samples (based on the U-²³⁰Th geochronometer) from Old Hillside Springs, Hillside Springs, North Hillside Springs, and Morning Glory in Upper Geyser Basin and from Firehole Lake in Lower Geyser Basin.

Schematic illustrating the conditions under which some travertine forms in Yellowstone caldera.

Photo of a bull elk wintering in Yellowstone National Park. Photo by Elizabeth Mordensky, March 5, 2024.

Melt inclusions (<50 micrometers in diameter) in a quartz crystal from the Huckleberry Ridge Tuff, erupted 2.1 million years ago. Photomicrograph taken by Behnaz Hosseini at Montana State University.

Schematic of the Huckleberry Ridge Tuff magma storage configuration, consisting of discrete batches of magma. Analyzing the compositions of melt inclusions can help paint this type of big picture of the magmatic system. Figure modified from Myers et al. (2016).

Map of the locations of water samples collected in and around Yellowstone National Park and detailed in the USGS Data Release "Historic Water Chemistry Data for Thermal Features, Streams, and Rivers in the Yellowstone National Park Area, 1883-2021." Colors indicate type of water sample.

Illustration of the crystal growth process that leads to melt inclusion entrapment. (a) A crystal (gray area) nucleates and grows. (b) As the magma cools, the crystal corners will grow more efficiently than crystal edges. (c) This growth process will lead to the entrapment of surrounding melt (orange area).

Vertical motion at GPS station P720, near the Slough Creek Campground in the northeast part of Yellowstone National Park, clearly shows a large annual cycle.

Histogram showing the number of earthquakes per 3-month period (quarter) in the Yellowstone region during 1973–2023.  Red bars represent all earthquakes located in the area, and blue bars indicate swarm seismicity.

Map of Yellowstone earthquakes that were located during 1973-2023. Red circles are earthquakes located in the Yellowstone region, and blue circles indicate swarm seismicity.  The size of the circle scales with the magnitude of the earthquake.

Map of areas predicted as having conditions favorable for fostering a hydrothermal system in the western United States.  Black dots are mapped hydrothermal systems.  From Mordensky et al., 2023 (https://www.sciencedirect.com/science/article/pii/S0375650523000160).

Trigger Action Response Plan (TARP) for the Yellowstone River Bridge replacement project.  The plan gives three levels of response for various conditions that might be encountered during drilling of bridge footings.  The level of severity is indicated by the colors, with green being least severe and red being most severe.

Map of Eocene igneous rocks associated with the Challis-Kamloops Belt. The Challis volcanics are indicated by red (extrusive) and orange (intrusive) colors.  The Absaroka volcanics are blue. Other Eocene rocks are shaded gray.  Map by Zach Lifton, Idaho Geological Survey.

Hydrograph showing discharge in cubic feet per second for Corwin Springs streamgage site on the Yellowstone River, MT, spanning 1889-2023.  The spike in 2022 is from the June floods of that year.

Plot of specific conductance, discharge, and temperature measured at the Yellowstone River at Corwin Springs, Montana, during early-mid 2023. The anomalous spikes in temperature and specific conductance on May 23, 2023, are thought to be when a large sand and bar was deposited at the site. May 23 is also the peak flow in 2023.