Images

A Hawaiian Volcano Observatory technician removes the electronics board on the Hualālai repeater station. The electronics board for the station was replaced with a 48-volt system electronics board as part of a station upgrade. USGS image by C. Parcheta.

A Hawaiian Volcano Observatory scientist drills holes to install a new electronics box for the Hualālai repeater station upgrade. USGS image by M. Warren.

During station maintenance at the Hualālai repeater, Hawaiian Volcano Observatory technicians installed a new webcam, the HLcam. This camera is located on Hualālai and provides view of Mauna Loa's northwest flank.

During the week of April 10, Hawaiian Volcano Observatory technicians upgraded the Hualālai repeater site, which is an important telemetry hub for volcano monitoring data. The site is located on the southeast side of Hualālai, at an elevation of 2,160 meters (7,090 feet) above sea level.

A Hawaiian Volcano Observatory technician replaces batteries on the Hualālai repeater station. The station, which relays monitoring signals from nearby stations back the observatory, is powered by batteries that store energy generated by solar panels. USGS image by M. Warren.

Map of the northwestern U.S., showing the approximate locations of the Yellowstone hotspot volcanic fields (orange) and Columbia River Basalts (gray).  Boundary of Yellowstone National Park is shown in yellow.  Inset shows physiographic map of southwest Montana and central Idaho.

Simplified map of the Wyoming Province—a craton composed of Archean-age continental crust. Archean- and Proterozoic-age rocks outcrop in many places within the Wyoming Province and are shown as dark grey blobs. The yellow blob highlights the location of the Hellroaring and Crevice plutons, a small portion of which are exposed in northern Yellowstone National Park.

Simplified geologic map of the Timber Hill basalt and underlying geology in the Sweetwater Hills. The Sweetwater Road is shown by red. Note the basalt flow generally rests on poorly cemented sediments of the Sixmile Creek Formation shown in orange.  Map by Jesse Mosolof (Montana Bureau of Mines and Geology).

USGS scientists work to recover sediment cores from Henrys Lake, Idaho. (Left): geologists traverse frozen Henrys Lake with coring supplies. USGS photo by Sylvia Nicovich, March 30, 2023.  (Right) Geologists lower the corer into the lake through a hole augured through the ice. USGS photo by Chris DuRoss, March 31, 2023.

Frying Pan Lake (also called Waimangu Cauldron), in New Zealand, sits within Echo Crater, which formed during the 1886 eruption of Tarawera.  A hydrothermal explosion from the crater in 1917 resulted in the formation of the hot spring "lake" by 1918.

Map of the distribution of pH for thermal pools within Norris Geyser Basin, Yellowstone National Park.  Cool colors are acidic, and warm colors are neutral to slightly basic.  These data were collected and organized using Geographic Information System (GIS) tools. Map by Jefferson Hungerford and Kiernan Folz-Donahue, Yellowstone National Park.

Volcanic deposits associated with the Absaroka volcanic province along the eastern and northern boundaries of Yellowstone National Park. The left panel shows the spread of the Absaroka Volcanic Supergroup (AVS) throughout Wyoming and Montana.

Isotopic composition of the primary volcanic groups of the Absaroka volcanic province (the Washburn, Sunlight, and Thorofare groups) and two volcaniclastic units, the Sepulcher formation and the Daly formation.

Landsat 8 nighttime thermal infrared image of Yellowstone National Park from January 31, 2023. Satellite-based thermal infrared data show areas on the surface that are warmer versus cooler, and they can be used to estimate surface temperature and the geothermal radiative heat output from the Yellowstone magmatic and hydrothermal system.

This image, taken early on January 6th, shows a lava fountain on the eastern portion of Halema‘uma‘u. Numerous areas of upwelling, like the one pictured here, are actively feeding the lava lake and re-surfacing material that was emplaced from activity in 2022. This fountain measured 16-33 feet in height (5-10 meters). 

A USGS Hawaiian Volcano Observatory geologist documents the new eruption within Halema‘uma‘u crater, at Kīlauea summit within Hawai‘i Volcanoes National Park. The eruption began just after 4:30 p.m. on January 5, 2023, and remains confined to Halema‘uma‘u crater. USGS image by D. Downs.

The KWcam webcam, on the west rim of Kīlauea caldera, was upgraded on January 4, 2023, to a more advanced model, which provides a slightly wider view and higher image quality. This should provide an improved view of any future activity in Halema‘uma‘u. In this photo, an HVO scientist begins the process of the webcam swap. USGS photo by M. Patrick.

Geology of the unconformity on Mount Everts in Yellowstone National Park.  Sketch at the top was made by geologist William Henry Holmes in 1878 and correctly identifies Cretaceous sediments overlain by much younger rhyolite rocks, including fine ash deposits (“tufa”).  The photo at the bottom shows the same outcrop as viewed from Mammoth Hot Springs (USGS

An example of the repeating seiche—a long-period oscillatory wave that can be present on a lake—measured over the course of a day by the lake-level sensor at the Grant Village boat dock on the West Thumb of Yellowstone Lake. The plot shows a cyclic variation of about 2 centimeters that occurs numerous times during June 13, 2021.

SP Crater (right foreground), like many volcanoes in Arizona’s San Francisco volcanic field, erupted mafic lava that lacks sanidine crystals.

Map of Yellowstone National Park lakes, rivers, and streams, with colors indicating the amount of arsenic in the water.  The Maximum Contaminant Level (MCL) defined by the Environmental Protection Agency for arsenic in drinking water is 10 micrograms per liter (µg/L).  In the vicinity of major geyser basins, especially on the Firehole and Madison Rivers, a