Images

Plot of size versus annual probability for hydrothermal explosion craters in Yellowstone National Park. The line is a model based on the energy required to form a crater of a specific size, and it is fit to known hydrothermal explosion craters in Yellowstone National Park.

(A) Water distribution in a quartz-hosted embayment measured with synchrotron Fourier Transform Infrared spectroscopy. Warmer colors indicate higher concentrations of water.  Dashed line shows a transect of water content that is modeled in panel (B) to indicate that the emplacement temperature of the ash flow deposit must have been about 500 °C (930 °F).

A clean hand sample of the Mount Jackson vitrophyre. This sample has a black, glassy groundmass with large (1–3 mm, or a small fraction of an inch), white phenocrysts suspended in the glass. Photo by Liv Wheeler, Montana State University, August 2024.

Shaded relief location map for the East Gallatin-Reese Creek fault system (EGRCFS) in northwest Yellowstone National Park (YNP). The location of the EGRCFS is shown as mapped in the U.S.

Abyss Pool is about 16 m (53 ft) deep and contains alkaline-chloride hydrothermal fluids that in the summer of 2024 had a temperature of 181 °F (83 °C).

Mud pots form in a few selected areas of West Thumb Geyser Basin where low-pH acidic fluids dissolve rocks and soil to produce clay-rich muds.  USGS photo by Pat Shanks, 2024.

Graph showing explosions recorded at Black Diamond Pool in Biscuit Basin, Yellowstone National Park, during 2006 through 2016. Confirmed events refer to eruptions that were witnessed, recorded by temperature loggers, or inferred from their aftermath. Unconfirmed events refer to eruptions that were questionable or might have been misattributed to Black Diamond.

Lidar hillshade maps of fault scarps that offset Pinedale glacial till along the East Gallatin-Reese Creek fault system (EGRCFS) near Fawn Creek (A) and Panther Creek (B). Fault scarps are visible as darker lineaments in the hillshade and are marked by the black arrows. Red rectangles on inset maps show location along the EGRCFS.

(A) Photomicrograph of a quartz-hosted embayment from the Mesa Falls Tuff. “MI” indicates a glassy inclusion of melt within the crystal. (B) Thickness (in centimeters) and extent of the Mesa Falls ash flow deposit (pink areas) and its source, Henrys Fork Caldera (dashed line).  Figure by Kenneth Befus, University of Texas at Austin.

Cinder Pool, located in the southwest part of 100 Spring Plain in Norris Geyser Basin, Yellowstone National Park. The pool was known for “cinders” made of sulfur that condensed after rising from a molten layer at the bottom of the pool, but after 2019 those cinders disappeared.  Photos from June 2018 (left) and June 2023 (right) by Lauren Harrison.

Exposure of the Mount Jackson Rhyolite Series vitrophyre at Gibbon River. Boulders of weathered, lichen-covered rock show how easy it is to overlook these new units. Photo by Liv Wheeler, Montana State University, August 2024.

This boulder is the largest that is confirmed to have been part of the July 23, 2024, hydrothermal explosion from Black Diamond Pool, Biscuit Basin, Yellowstone National Park.  The tape measure is 50 centimeters (20 inches) long.  Black Diamond Pool and a boardwalk are in the background.

High-resolution Planet satellite image of Biscuit Basin, Yellowstone National Park, from July 24, 2024.  The image shows changes that occurred as a result of the July 23, 2024, hydrothermal explosion from Black Diamond Pool, including deposition of material in the vicinity of the pool and a plume of discolored water in the Forehole River.

Webicorders of Yellowstone Seismic Network stations YMR (West Entrance road) and YNM (Norris Geyser Basin Museum) showing traffic signals (left) and visitors walking (right) during daytime hours.  Both records span the entire 24-hour period of July 23, 2024, MDT. 

Cover of the Yellowstone Volcano Observatory response plan for geological hazards in the Yellowstone region.  The report can be accessed at https://pubs.usgs.gov/circ/1351/.  Cover features a photograph by Mike Poland and frame captures from a video by Juliet Su.

Webicorders of Yellowstone Seismic Network stations YMR (West Entrance road) and YNM (Norris Geyser Basin Museum) showing traffic signals (left) and visitors walking (right) during daytime hours.  Both records span the entire 24-hour period of July 23, 2024, MDT. 

Webicorders of Yellowstone Seismic Network stations YMR (West Entrance road) and YNM (Norris Geyser Basin Museum) showing traffic signals (left) and visitors walking (right) during daytime hours.  Both records span the entire 24-hour period of July 23, 2024, MDT. 

Webicorders of Yellowstone Seismic Network stations YMR (West Entrance road) and YNM (Norris Geyser Basin Museum) showing traffic signals (left) and visitors walking (right) during daytime hours.  Both records span the entire 24-hour period of July 23, 2024, MDT. 

Aerial view of Biscuit Basin, Yellowstone National Park, showing debris deposited by the July 23, 2024, hydrothermal explosion from Black Diamond Pool.  Major features are labeled.  The main debris field (within dashed yellow line) has a gray appearance.  Photo taken by Joe Bueter, Yellowstone National Park, on July 23, 2024.

Webicorders of Yellowstone Seismic Network stations YMR (West Entrance road) and YNM (Norris Geyser Basin Museum) showing traffic signals (left) and visitors walking (right) during daytime hours.  Both records span the entire 24-hour period of July 23, 2024, MDT. 

High-resolution Planet satellite image of Biscuit Basin, Yellowstone National Park, from July 21, 2024.  This work utilized data made available through the NASA Commercial Smallsat Data Acquisition (CSDA) Program.  Data are copyright, Planet Labs Inc. 2024, all rights reserved.