Images

Cross section through the Earth showing the ground surface with an embedded pressure source (red circle)—the so-called “Mogi model”—beneath the ground.  When this pressure source expands, the ground surface inflates like a balloon (the opposite occurs when the pressure in the source decreases).  Dashed black line shows, in an exaggerated way, how the shape

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.

Photo looking north from the north shore of Yellowstone Lake. The photo was taken from a level bench, or terrace, which marks a previous high stand of the lake.  In the middle distance (between the two red lines), the ground slopes up to second, higher-level terrace that indicates an even higher past lake level.

USGS scientist Laura Clor performing maintenance on the SNIF multi-GAS station on Mount St. Helens, Washington.

Interior of the SNIF multi-GAS enclosure on Mount St. Helens, Washington

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

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.

Thin section image of a lava sample from Yellowstone using a polarizing microscope. The mineral assemblage is representative of many of Yellowstone’s basaltic rocks. The three large and colored crystals (known as phenocrysts) in the center of the image are the mineral olivine.

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.

In the first few minutes of Steamboat's eruptions, it has often been measured well over 300 ft. with a few exceptional eruptions measured by visitors at over 400 ft.!  In this example, done using a rangefinder by a Yellowstone National Park ranger, it comes in at 334.9 ft. For comparison, the Lower Falls of the Yellowstone is about 308 ft.

National Park Service scientist using a camera paired with a GPS receiver to obtain images of Castle Geyser, Yellowstone National Park, in June 2019.

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.

Comet NEOWISE is seen with the Roosevelt Arch in the foreground at the north Entrance of Yellowstone National Park.  The town of Gardiner, Montana, is in the background.

Panoramic photo of Hayden Valley looking east toward the Yellowstone River from the Mary Mountain trail.

A small stream, Violet Creek, winds its way through Hayden Valley in Yellowstone National Park.

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).

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).