Images

Example of some of the new layers available in the Geology of Yellowstone Map as of early 2021. Shown here are the locations of various monitoring instruments and water sample sites overlain on a thermal infrared satellite image. Lighter colors on the infrared image show more radiant (warmer) areas, whereas dark areas are less radiant (cooler).

Seismic stations (white triangles) around Yellowstone Lake as seen on the online Geology of Yellowstone Map. Inset shows a seismogram for station YLA that can be accessed by clicking on the feature and following the “Seismogram” link in the popup box.

Cycles in Kīlauea's summit eruptive vigor were present on January 22 and 23, with the lava channel at Halema‘uma‘u's western fissure alternating between high and low flow rates over periods of 5-6 minutes. USGS photos by M. Patrick.

Active lava was again limited to the western half of the lava lake in Halema‘uma‘u at Kīlauea Volcano's summit. The western vent remained active with cycles of eruptive vigor in the open channel lasting 5-6 minutes. USGS photo by M. Patrick.

Active lava reached as far as the central lake in Halema‘uma‘u at Kīlauea's summit, on the east side of the main island, where crustal foundering was occasionally happening. USGS photo by M. Patrick.

Activity at the west vent within Halemaʻumaʻu crater on January 22 included frequent spattering from multiple locations and an open lava channel which drops 20 meters (65 feet) from its source to the lava lake surface.

Between overcast and rainy weather, HVO field crews took this photo at 3:34 p.m. HST on January 21, 2021, from the south side of Kīlauea's summit caldera. The photo shows Halema‘uma‘u's active west vent, which overflowed its tubed-over lower half at 2:51 p.m.

This photo, taken at just after 6 p.m. HST on January 19, shows that the western fissure continues to send lava into Halemʻaumaʻu crater through an open channel into the lava lake. The western side of the lava lake has an incandescent surface, while the eastern portion is more crusted over.

The western fissure at Kīlauea's summit continues to send lava into Halemʻaumaʻu crater through an open channel into the lava lake. Around sunset on the evening of January 19, field crews observed a minor collapse event of the spatter rampart on its northern rim and the channel margins at 5:46 p.m. HST.

On the evening of January 17, the vent on the north side of the western fissure in Halema‘uma‘u at Kīlauea's summit activated and seemed to become the dominant vent overnight. This vent is the one on the right in this photo. The vent on the left, which was the dominant vent over the past week, seemed less energetic today. USGS photo by M. Patrick.

A close up of the vent area at the western fissure within Halema‘uma‘u at Kīlauea's summit. The two main vents were exhibiting low fountaining while a small vent in the middle had sporadic, weak spattering. USGS photo by M. Patrick.

A close up of the southwest portion of the lava lake within Halema‘uma‘u, just south of the west fissure. The lava lake at Kīlauea's summit is perched, and is contained by a steep levee 2-3 meters (yards) high. USGS photo by M. Patrick.

Sunlight interacts with volcanic gas from Kīlauea's summit lava lake and western fissure in this late afternoon view. The western fissure has built a spatter cone on the steep walls of Halema‘uma‘u, with lava spilling into the active lake, which forms the lower right portion of the photo.

A closer view of the low fountaining at the western fissure in  Halema‘uma‘u at Kīlauea's summit. The rim of the cone is built from accumulated deposits of spatter, and large chunks of the cone rim were observed to collapse from time to time. USGS photo by M. Patrick

Low fountaining continues at the western fissure, supplying lava to the lava lake in Halema‘uma‘u crater, at the summit of Kīlauea. The vent has formed a spatter cone around the fountaining, with lava spilling into an open channel that plunges into the lake.

Photos from a Scanning Electron Microscope (SEM) showing reacted rhyolite fragments at the end of the laboratory experiments. (a) Image magnified by 500 times showing the rhyolite after it reacted with water at 250 degrees Celsius (482 F). The reacted rhyolite fragments show very little change compared with the unreacted fragments.

Mudpot located in the Mud Volcano thermal area of Yellowstone National Park.  This type of thermal feature indicates an acid-sulfate system.

Steam vents along the Yellowstone River near Mud Volcano thermal area, Yellowstone National Park.

The west vent in Halemaʻumaʻu erupting and building a spatter cone complex, with lava cascades feeding a growing lava lake at Kīlauea summit. USGS photograph from January 11, 2021, by B. Carr.

A close up view of the spatter cone over the west vent, in Halema‘uma‘u crater at the summit of Kīlauea. This photo was taken on January 10, 2022, from within the closed area of Hawai‘i Volcanoes National Park. Hawaiian Volcano Observatory geologists monitor the eruption from within the closed area with NPS permission. USGS photo by M. Patrick.

Around sunset on Saturday (January 9, 2021), a break in the rain allowed HVO scientists to visit and monitor the ongoing eruption in Halema‘uma‘u. The west vent is still actively effusing lava, but outflow into the lava lake is increasingly sluggish, as evidenced by slow-moving crustal plates near the once-vigorous vent outlet.