Images

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.

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.

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 Thielsen (2,799 m or 9,182 ft) is an extinct volcano north of Crater Lake, Oregon that last erupted 250,000 years ago. Aerial view.

Mount Thielsen (2,799 m or 9,182 ft) is an extinct volcano north of Crater Lake, Oregon that last erupted 250,000 years ago. Diamond Lake is in the background.

Bystanders watch steam rising from Queens Bath as lava flow enters the water. Lava overran Highway 130 at 0748 Hawaii Standard Time on the same morning at the western margin of the Kapa'ahu flow. By the end of the day, Punalu'u heiau was overrun, and Queens Bath was filled with lava.

pāhoehoe flow crosses Highway 130 and enters Kalapana, Hawai‘i, Kīlauea Volcano

pāhoehoe flow advancing through mango trees toward a house in Kalapana Gardens subdivision, Hawai‘i

Pu‘u ‘Ō‘ō cone is visible on skyline at center. In the foreground are the Mauna Kea Congregational Church (right of center) and fishponds (lower left) bounded by the Hakuma horst, the uplifted, elongate block at lower left. View is to the northwest.

The last dome-building eruption of Mount St. Helens during the 1980s occurred in October 1986. A new lobe was extruded, increasing the dome's height to 925 feet (282 meters), making it taller than a 77-story building. In volume, the dome was nearly 40 times the size of Seattle's Kingdome stadium.

View of the Spirit Lake outlet tunnel, built in 1985, that allows water to drain out of Spirit Lake safely and maintain the lake's water level 100 ft (30 m) below the estimated overtopping level.

New pāhoehoe flows are overriding dark ‘A‘ā flows from Pu‘u ‘Ō‘ō, 3 km uprift (in background). The Pu‘u ‘Ō‘ō conduit failed on July 18, triggering fissure eruptions both up- and downrift of the cone. On July 20 (beginning of episode 48), the fissure at this site began to erupt, initiating 5.5 years of near-continuous effusion from the Kupaianaha vent.

Oblique aerial view of San Andreas Fault (between white arrows) in southeastern Coachella Valley, near Red Canyon; view to the west.

The Mameyes, Puerto Rico, landslide, 1985. This landslide destroyed 120 houses and killed at least 129 people. The catastrophic slide was triggered by a tropical storm that produced extremely heavy rainfall.

Aerial view of Armero destroyed by lahars from Nevado del Ruiz volcano, Colombia, on November 13, 1985.

Lava fountain heights at Pu‘u ‘Ō‘ō reached a maximum of 295 m (970 ft) around the time this photo was taken during episode 38.

Three Sisters volcanoes (left to right - South, Middle, and North) viewed from the south, Oregon. Foreground rhyolite Newberry flow is one of most recent eruptive units (2.2 ka).

The lava dome was taller than a 66-story building and almost as wide as the length of nine football fields. The dome completely fills the camera's field of view. Compare with image taken August 22, 1981 from the same location with the same camera.

Hydrologists measuring stream discharge and took water samples to determine how much sediment is suspended in the stream and how much sediment is moving along the streambed.