Images

Comparison of photos from Giant and Castle Geysers separated by almost 150 years. These images suggest almost no changes to the geyser structure implying that large geysers form over thousands of years. 

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.

A view into the Absaroka Mountains in northeastern Yellowstone National Park. While the Absarokas of today look a little different due to glacial activity, these are the same mountains that existed over the last 53 million years, well before the arrival of the Yellowstone hot spot.

Geologists from Montana State University study an outcrop of diorite (a silicic igneous rock that cooled slowly beneath the ground). An outcrop of this size is important because it is easier to see any structural relations along with rock composition.

Newly identified ash flow sheets within the Yellowstone–Snake River Plain volcanic province (Y-SRP).  The small inset in the center shows the track of the Yellowstone hotspot and its associated eruptive centers in light gray (M—McDermitt; OH—Owyhee-Humboldt; BJ—Bruneau-Jarbidge; TF—Twin Falls; P—Picabo; H—Heise; Y—Yellowstone).

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).

Simplified Geologic Map of Yellowstone, modified from USGS I-711 by Marli Miller, University of Oregon. All rock material resulting from the major caldera-forming eruptions are labelled at Qt, where the dashed caldera boundary highlights the scale of these events. Older volcanic, sedimentary and metamorphic rocks are found outside of this boundary.

A Light Detection and Ranging (LiDAR) shaded relief image overlaid on an aerial imagery basemap. The Sulphur Hills, part of the Sour Creek Resurgent Dome, are visible in the upper half of the image, while the floodplain and meanders of Pelican Creek are visible at the bottom.

Geology of Yellowstone Map zoomed into the Lower Geyser Basin. This view shows a park-wide geologic map overlaid on a shaded relief layer from a digital elevation model. Red diamonds and black circles show geysers and gas sample locations, respectively.

Archive view of the Yellowstone Volcano Observatory website in 2001.

Archive view of the Yellowstone Volcano Observatory website in 2009.

Sunset lake in Black Sand Basin of Yellowstone National Park

Grand Prismatic Spring in Midway Geyser Basin Yellowstone National Park on October 19, 2017.

The relationship between Δ30 and N2/3He ratios in hydrothermal gases from Iceland and Yellowstone. Δ30 and N2/3He ratios are shown for samples collected from gases in Iceland (yellow circles) and Yellowstone (red circles). The Yellowstone mantle-endmember is arguably indistinguishable in terms of N2/3He from the convecting upper mantle (grey diamonds).

Imperial Geyser hot spring pool in Yellowstone National Park is about 30 m (about 100 ft) across and contains alkaline-Cl waters with a steam vent in the pool and mudpots outside the pool area (in the upper right part of this photo). USGS Photo by Pat Shanks, 2019.

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.

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).

Sabrina Brown collecting samples from Yellowstone Lake core YL16-2C at the National Lacustrine Core Facility (LacCore) at the University of Minnesota.

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.

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