Images

Sherman Crater (foreground) below the summit of Mount Baker, Washington.

Pahoehoe lava flows are fed by overflows from the fissure 8 lava channel. Geologist ground crews photographed this flow along Nohea Street in Leilani Estates subdivision.

Slow cooling of a basaltic lava flow that was erupted about 500,000 years ago resulted in the formation of hexagonal columns at Sheepeater Cliff, in Yellowstone National Park.

Crater Lake bathymetric map showing the geology of the caldera floor with post-caldera eruptive units. Oregon

Northeast crater wall above Sugar Bowl, Mount St. Helens with annotated deposits from some of the Spirit Lake Stage eruptive periods. Photograph from late summer 2003.

Norris-2003. Location map of seismometers and GPS receivers deployed to help monitor the Norris Geyser Basin.

A 1.5-million-year-old basaltic lava flow in the canyon wall of the Yellowstone River as viewed from Calcite Springs Overlook near Tower Junction in Yellowstone National Park.  Slow cooling of this lava flow resulted in the formation of vertical columns.  Glacial gravels are present above and below the lava flow.

Gas bubbles through a sample bottle containing alkaline solution, allowing for separation of different gas phases.

Mount Baker summit, Washington. Coleman Glacier to the left and Easton Glacier to the right. Lower peak on the right is the edge of Sherman Crater. View to east.

View to the southeast through the area affected by the increased thermal output at Norris' Back Basin in the summer of 2003. The foreground shows steaming areas where boiling water and steam have approached the surface, resulting in increased ground temperatures.

Black Buttes stratovolcano and south side of ice-mantled Mount Baker. Aerial view northeastward. For Black Buttes, strata of the two highest crags (Lincoln Peak, left, and Colfax Peak) display opposing 308 dips that frame the gutted edifice.

_{Eruption cloud, from the east crater of Anatahan Volcano, rising to a height of about 15,000 feet, on May 10, 2003. View from the NE side of the island, looking in a southwesterly direction.}

Plantation forestry on the slopes of Mt Etna during the 2002 eruption, unaffected by several millimetres of fallen ash.

Isobars (gray) represent locus of values for dissolved H₂O andCO₂ in rhyolitic melt in equilibrium with H₂O–CO₂ vapor at 800°C and selected pressures. Isopleths represent locus of rhyolitic melt compositions in equilibrium with the given vapor compositions (20, 50 and80 mol% H₂

Bathymetric map of Yellowstone Lake showing hydrothermal features in the north part of the lake, including Elliott's Crater, Mary Bay, and Deep Hole.  Colors correspond to lake depth, with cooler colors indicating greater depths.

Quito's international airport was covered with 3-5 mm of ash from the 3 November 2002 eruption of Reventador Volcano, located ~60 miles to the east of the Ecuadorean capital. The airport was closed for 8 days while clean up took place.

MODIS satellite image of New Zealand’s North Island acquired on October 23, 2002 (https://earthobservatory.nasa.gov/images/3101/new-zealand).  Lake Taupō is located in the center of North Island.

Map of the northwestern U.S., showing the approximate locations of Yellowstone hotspot volcanic fields (orange) and Columbia River Basalts (gray). Boundary of Yellowstone National Park is shown in yellow. Modified from Barry et al. (GSA Special Paper 497, p.

Scientist from the USGS collects a gas sample into an evacuated/vacuum flas from a steam vent near the Shoshone Geyser Basin.

Collapse of Kīlauea's caldera floor has exposed South Sulphur Bank, prominent in the mid-19th century but covered as lava flows filled the caldera. The flat top of the white deposit shows how high the caldera fill reached. As the caldera floor dropped in mid-June 2018, South Sulphur Bank was again exposed.

Obsidian Cliff exposes the interior of a thick rhyolite lava flow erupted about 180,000 years ago. The vertical columns are cooling fractures that formed as the thick lava flow cooled and crystallized. The flow consists of obsidian, a dark volcanic glass.