Images

Eruptions in the Cascade Range during the past 4000 years. USGS GIP 64

Morning aerial view looking northwest up the valley of Sun Creek. Applegate Peak caps the prominent rock wall of the west side of Sun Notch at the caldera rim. Northwest caldera wall is visible on opposite side of Crater Lake through Sun Notch. Grayback Ridge in foreground is thick lava of pre-Mazama rhyodacite (410-460 ka).

UNAVCO engineers drilling a borehole for instrument installation (left). Aerial view of borehole casing used to protect instruments from the elements found below the surface (right).

HVO geologist downloads images collected with infrared cameras set up on the rim of Halema‘uma‘u Crater. The cameras are aimed at an erupting lava lake to conduct a thermal survey of the lake's surface.

Seismologist installing equipment at station NED on Mount St. Helens, Washington. Mount Rainier in distance.

Gas flux measurement being taken over altered ground at Brimstone Basin, Yellowstone.

Gas flows up, appearing to boil, through the water of Alluvium Creek, Brimstone Basin, Yellowstone. Large funnel is used to trap gas, which is then sent to a collection bottle through the tubing.

Sulfur flow (darker gray area) on an altered ground surface at Brimstone Basin, Yellowstone Lake in background.

Hawaiian Volcano Observatory field geologists track activity at fissure 8 (pictured in the background). Crews collect fissure 8 tephra (Pele's hair, pumice, and other lightweight volcanic glass fragments) for geochemical analyses and characterization of changes in lava fountain behavior.

The USGS Hawaiian Volcano Observatory (foreground) is located on the caldera rim of Kilauea Volcano, Hawai'i—the most active volcano in the world.  The observatory's location provides an excellent view of summit eruptive activity, which began in 2008.

The Hawaiian Volcano Observatory, the first volcano observatory in the United States, is located on the west rim of Kīlauea Volcano's summit caldera in Hawai‘i Volcanoes National Park. A volcanic gas plume rises from a vent that opened in 2008 at the base of the south wall of Halema‘uma‘u Crater. Crater Rim Drive in foreground.

The U.S. Geological Survey's Hawaiian Volcano Observatory, the first volcano observatory in the United States, is located on the west rim of Kīlauea Volcano's summit caldera in Hawai‘i Volcanoes National Park. A volcanic gas plume rises from a vent that opened in 2008 at the base of the south wall of Halema‘uma‘u Crater. Crater Rim Drive in foreground.

Volcanic-gas plumes mark the sites where lava flows from Pu‘u ‘Ō‘ō enter the ocean on Kīlauea's south coast (far left), the Pu‘u ‘Ō‘ō cone (left) on the East Rift Zone, and Halema‘uma‘u Crater at the summit (right). Structures visible in middle left primarily located around the Volcano Golf and Country Club and Kīlauea Military Camp.

The Hawaiian Volcano Observatory perched on the west rim of Kīlauea Volcano's summit caldera, overlooks Halema‘uma‘u Crater, where a new vent that opened in March 2008 emits a volcanic gas plume.

The USGS Hawaiian Volcano Observatory (foreground) is located on the caldera rim of Kilauea Volcano, Hawai'i—the most active volcano in the world.  The observatory's location provides an excellent view of summit eruptive activity, which began in 2008.

Lidar instrument uses light pulses to measure distances to the ground surface in the Kīlauea Caldera, Hawaii. Measurements are used to make a Digital Elevation Model - a very accurate topographic map.

Narrow Gauge spring, Mammoth Hot Springs, Yellowstone National Park.  Vent area is between the two trees on top of the travertine deposits.  Terraced pools form due to deposition of travertine from the fluids as they cool and degas carbon dioxide.

Incandescent arcs trace the path of lava fragments cast out during a tephra-jet explosion at the Waikupanaha ocean entry in 2008. This is a relatively small explosion, reaching a few tens of meters (yards) height, while one earlier in the day was nearly 70 meters (230 ft) in height.

When lava from the Pu'u 'Ō'ō-Kupaianaha eruption, active since 1983, meets the ocean, large littoral explosions can result.

The early morning helicopter overflight of the lower East Rift Zone shows lava continuing to enter the sea at Ahalanui. The southern margin of the flow remains about a quarter mile from the boat ramp at Isaac Hale Park (jetty visible in the center left of the photo). View to the northeast.

Crater Lake Caldera with Wizard Island cinder cone and lava flows, some of the youngest features in the caldera as seen from Merriam Point. Viewed toward the south. Oregon