Top: Dark glassy deposits of melted volcanic ash on leading edge of highâ€pressure turbine nozzle guide vanes. Bottom: Accumulation of unmelted volcanic ash in the high-pressure turbine rotor.
Images
Top: Dark glassy deposits of melted volcanic ash on leading edge of highâ€pressure turbine nozzle guide vanes. Bottom: Accumulation of unmelted volcanic ash in the high-pressure turbine rotor.
Lava flows from a lava tube into the sea near Kupapau Point on Hawai'i Island. From the Kilauea East Rift Zone (ERZ) eruption, November 27, 1989. Episode 48 of the Kupapau Lava Flow.
Lava flows from a lava tube into the sea near Kupapau Point on Hawai'i Island. From the Kilauea East Rift Zone (ERZ) eruption, November 27, 1989. Episode 48 of the Kupapau Lava Flow.
Lava flows from a lava tube into the sea near Kupapau Point on 11/27/1989. From the Kilauea East Rift Zone (ERZ) eruption, eruption pisode 48, Kupapau lava flow. Hawai'i Island.
Lava flows from a lava tube into the sea near Kupapau Point on 11/27/1989. From the Kilauea East Rift Zone (ERZ) eruption, eruption pisode 48, Kupapau lava flow. Hawai'i Island.
A downtown building at the corner of Alice and 13th Streets lost part of its unreinforced facade and brick masonry.
A downtown building at the corner of Alice and 13th Streets lost part of its unreinforced facade and brick masonry.
Pahoehoe ropes form in the Wahaula Lava Flow across from Wahaula Visitor Center on Hawai'i Island during the Kilauea East Rift Zone (ERZ) eruption on 6/15/89.
Pahoehoe ropes form in the Wahaula Lava Flow across from Wahaula Visitor Center on Hawai'i Island during the Kilauea East Rift Zone (ERZ) eruption on 6/15/89.
Angle and distance measurements to the Mount St. Helens' flanks were taken periodically to monitor for deformation similar to the 1980 bulge. Station northeast of volcano.
Angle and distance measurements to the Mount St. Helens' flanks were taken periodically to monitor for deformation similar to the 1980 bulge. Station northeast of volcano.
Sediment retention dam on the North Fork Toutle River is designed to help stop downstream movement of sediment near where it begins on Mount St. Helens' debris avalanche deposit.
Sediment retention dam on the North Fork Toutle River is designed to help stop downstream movement of sediment near where it begins on Mount St. Helens' debris avalanche deposit.
Fumaroles of cold, dry CO2 such as this one on a lava flow erupted in 1938 from Nyamuragira Volcano, Zaire, can be exceptionally dangerous because the gas discharge is invisible. The density difference between CO2 and air is so great that a sharp boundary can persist between them.
Fumaroles of cold, dry CO2 such as this one on a lava flow erupted in 1938 from Nyamuragira Volcano, Zaire, can be exceptionally dangerous because the gas discharge is invisible. The density difference between CO2 and air is so great that a sharp boundary can persist between them.
Large-scale poster describing USGS work.
The USGS, in cooperation with the UK Institute of Oceanographic Sciences (IOS) and others, took images of the seafloor 200 miles around the Hawaiian Islands using GLORIA. GLORIA is a long-range sonar that gives a bird’s-eye view of the seafloor.
Large-scale poster describing USGS work.
The USGS, in cooperation with the UK Institute of Oceanographic Sciences (IOS) and others, took images of the seafloor 200 miles around the Hawaiian Islands using GLORIA. GLORIA is a long-range sonar that gives a bird’s-eye view of the seafloor.
A thin-walled lava bubble expands and bursts. These "bubble bursts" occur when seawater infiltrates the lava tube system near the shore. Such bubble bursts produce translucent sheets of spatter, or limu o Pele.
A thin-walled lava bubble expands and bursts. These "bubble bursts" occur when seawater infiltrates the lava tube system near the shore. Such bubble bursts produce translucent sheets of spatter, or limu o Pele.
Glacial end moraine deposits on south flank of Mauna Kea, Hawai‘i
Glacial end moraine deposits on south flank of Mauna Kea, Hawai‘i
12,398 ft elev according to USGS Geographic Names Information System
12,398 ft elev according to USGS Geographic Names Information System
The light colored lava flows in foreground are part of the older Laupahoehoe Volcanics, erupted between 70,000 to 13,000 years ago. one of the youngest cinder cones erupted by the volcano,
The light colored lava flows in foreground are part of the older Laupahoehoe Volcanics, erupted between 70,000 to 13,000 years ago. one of the youngest cinder cones erupted by the volcano,
Pu‘u Keonehehe‘e and the two small cones immediately to the northwest (left) are among the youngest cones erupted on the volcano, as recent as about 4,000 years ago. The other cones in this view are part of the Laupahoehoe Volcanics, but much older, dating to 70,000 years ago.
Pu‘u Keonehehe‘e and the two small cones immediately to the northwest (left) are among the youngest cones erupted on the volcano, as recent as about 4,000 years ago. The other cones in this view are part of the Laupahoehoe Volcanics, but much older, dating to 70,000 years ago.
The deposits are found between about the 11,000 and 12,000 ft elevation. The cinder cones left of the glacial deposits were erupted between 70,000 and 13,000 years ago, and the irregular surface below the cones and glacial deposits consist of lava flows erupted during the same time frame.
The deposits are found between about the 11,000 and 12,000 ft elevation. The cinder cones left of the glacial deposits were erupted between 70,000 and 13,000 years ago, and the irregular surface below the cones and glacial deposits consist of lava flows erupted during the same time frame.
Deformation measurements on the Mount St. Helens' dome; three geologists in middle bottom of this aerial photograph.
Deformation measurements on the Mount St. Helens' dome; three geologists in middle bottom of this aerial photograph.
Glacial deposits of the Waihu Glacial Member exposed in unnamed gulch on southwest flank of Mauna Kea at about 3,020 m (9,900 ft) elevation. Ages of both the glacial deposits and lava flows are poorly known, estimated to within about 150,000 to 70,000 years ago. Pole is 1.5 m (5 ft) long.
Glacial deposits of the Waihu Glacial Member exposed in unnamed gulch on southwest flank of Mauna Kea at about 3,020 m (9,900 ft) elevation. Ages of both the glacial deposits and lava flows are poorly known, estimated to within about 150,000 to 70,000 years ago. Pole is 1.5 m (5 ft) long.
Lava bubble bursts are a relatively mild form of explosion that occurs when a lava tube at, or below sea level, fractures abruptly, allowing seawater to enter the tube system. As the infiltrating seawater comes into contact with molten lava in the tube, the water is heated to steam in an instant.
Lava bubble bursts are a relatively mild form of explosion that occurs when a lava tube at, or below sea level, fractures abruptly, allowing seawater to enter the tube system. As the infiltrating seawater comes into contact with molten lava in the tube, the water is heated to steam in an instant.
Explosive interaction between lava and seawater blasts a tephra jet consisting of steam, hot water, black tephra, and molten fragments into the air. This explosion is directed primarily toward the sea, but many explosions also send a shower of lava more than 10 to 20 m inland.
Explosive interaction between lava and seawater blasts a tephra jet consisting of steam, hot water, black tephra, and molten fragments into the air. This explosion is directed primarily toward the sea, but many explosions also send a shower of lava more than 10 to 20 m inland.
Mount Adams southern view as seen from Trout Lake, Washington. Trout Lake sits on thick lahar deposits that originated as a debris avalanche 6,000 years ago.
Mount Adams southern view as seen from Trout Lake, Washington. Trout Lake sits on thick lahar deposits that originated as a debris avalanche 6,000 years ago.