Images

Maps displaying the stages of evolution of the more recent cycle of volcanism associated with Yellowstone Caldera. From Finn and Morgan, 2002 (High-resolution aeromagnetic mapping of volcanic terrain, Yellowstone National Park).

Color-shaded topographic relief map of the Yellowstone Plateau-Snake River Plain volcanic province showing the track of the Yellowstone hot spot. Figure by Ken Pierce and Lisa Morgan.

The sun rises at Mount St. Helens (pictured in the distance), with low-level clouds covering Coldwater Lake. The view is from the Coldwater Science and Learning Center, the site of the 2018 GeoGirls field camp program.

This thermal map was constructed by merging about 1300 images from a morning helicopter overflight, and shows the distribution of some of the prominent thermal features in the caldera. The most conspicuous area is a region of high temperatures in the deepest part of the collapse depression, in the area of Halema‘uma‘u.

View of a clear blue hot spring pool of alkaline chloride fluid with silica sinter apron around it at Biscuit Basin.  This pool is generally close to the boiling temperature (200℉, 93℃) at this altitude (7200 ft, 2195 m).

Alkaline-chloride waters from an eruption of Old Faithful flow over the edge of the white silica sinter terrace into the Firehole River.  The orange coloration on the sinter terrace is due to thermophilic (high temperature) bacteria living in the warm fluids.  Old Faithful Inn is in the background, with the wooded Summit Lake rhyolitic lava flow behind.&nb

Only small amounts of sulfur dioxide (SO2) and hydrogen sulfide (H2S) are currently being released from Kīlauea, but they chemically react with each other (oxidation-reduction reaction) to form the bright yellow sulfur deposits visible on the crater walls within Halema‘uma‘u.

Argon geochronology lab in Menlo Park, California.

A scientist takes a gravity reading at a station located on the down-dropped block of Kīlauea caldera, which subsided as an intact structure, while a second gravity instrument (foreground) records data. Many of the preexisting gravity stations, which have been measured for years, survived Kīlauea's 2018 summit collapse.

USGS Hawaiian Volcano Observatory staff, September 2018.

Microprobe laboratory in Menlo Park, California.

This aerial view of the western part of Kīlauea Volcano's caldera was taken on August 6, 2018. The down-dropped block is faulted about 120 m (400 feet) below the caldera floor. Many 19th-century lava flows are exposed in the fault scarps. Halema‘uma‘u (not visible) is to the left of this photo. USGS photo by D.Swanson.

New thermal feature beneath the boardwalk on Geyser Hill, Upper Geyser Basin. Boards removed for better observation. Pump Geyser is mound at end of boardwalk. Old Faithful Inn in distance.

An unnamed but charismatic thermal feature alongside Ferris Fork, near the Bechler River. The center of the pool is roiling with gas bubbles, but not boiling! The pool is only about 180 degrees F (81 degrees C), and all the gas is bubbling up from underground.

Mules loaded with sampling equipment and supplies for a mission to collect gas and thermal water samples from the Bechler River area in the southwest part of Yellowstone National Park. 

Following the draining of magma from Pu‘u ‘Ō‘ō on April 30, 2018, the crater was roughly 356 meters (1168 feet) deep. The upper part of the crater was flaring, with the deepest portion a narrower cylindrical shaft.

Explosive eruption columns of ash rising from Halema‘uma‘u at 11:15 a.m. on May 18, 1924 (top) and at 11:05 a.m. on May 15, 2018 (bottom) look similar.

The video was taken during an overflight of Pu‘u ‘Ō‘ō crater on Kīlauea's middle East Rift Zone. No major changes were observed, but the crater shape continues to change due to continued rockfalls.

Landsat-8 nighttime thermal infrared image from April 2017 showing the Tern Lake area. In Yellowstone, temperatures are extremely cold at night in the winter, and most lakes are frozen (dark pixels). West Tern Lake seems to be thawing here - perhaps it receives some thermal waters from nearby hot springs.

Aerial view due south of the Mono Lake-Long Valley volcanic region. Inset map shows locations of latest Pleistocene–Holocene silicic magmatic centers relative to Long Valley caldera. Rhyolites of the Mono–Inyo chain are shown in pink, and the dacitic–rhyodacitic Mammoth Mountain dome complex is shown in blue. U.S.

View into Halema‘uma‘u from the west rim of Kīlauea's summit caldera. USGS photo: J. Kauahikaua, 03 March 2019