Images

Slope map of Mauna Loa, including lava flows erupted since 1823 (gray), showing the approximate number of hours or days it took for a flow to advance from the vent location to the ocean or maximum reach of a flow. One flow that moved down the steep slopes on west flank of Mauna Loa reached the ocean in as little as 3 hours after the vent started erupting in 1950.

Pyroclastic flow (dense darker grey billowing mass) travels down slope of Mayon volcano, Philippines while ash column rises from the vent. Dilute, lighter-colored ash billows off leading edge.

Map of hazard zones for ground fractures and "small-scale" subsidence for the Island of Hawai‘i. Subsidence and fracturing events are frequent in zone 1, which covers the summit and rift zones of Kīlauea and Mauna Loa volcanoes, but are somewhat less frequent in zone 2, on the south flank of Kīlauea.

The older or original suggested location of this rift is shown with a blue dashed line. Black arrows show one possibility for the westward migration of the Nīnole Hills rift to the location of Mauna Loa's current Southwest Rift Zone (yellow dashed line). The South Kona Slump and ‘Ālika-1 and ‘Ālika-2 landslides are shown off the west coast of the island.

Aerial view of Haleakalā Crater northward to Ko‘olau Gap. Sharp rimmed crater in near ground is Ka Lu‘u o ka ‘Ō‘ō.

Top panel shows a continuous GPS station located in Yellowstone National Park. The antenna is secured to the ground by several metal poles, and a nearby set of solar panels provides power to the station. Lower panel shows a semipermanent GPS station, with a small solar array for power and an antenna located close to the ground.

Researchers map the bottom of Castle Lake, near Mount St. Helens. For three days, researchers ran a small boat over the lake surface equipped with an acoustic Doppler current profiler (ADCP). The ADCP bounces an acoustic wave off the bottom that is reflected back to a mobile receiver in the boat.

No date exists for this photograph, but the image is likely circa 1900. Note the postcard copyright date of 1903.

This notice was posted at campgrounds around Baker Lake by the US Forest Service in June 1975. Normally, Baker Reservoir approaches capacity during mid-summer. At most other times, reservoir levels are low enough to impound lahars the size of those that occurred in 1843.

Boulder Creek leading from Mount Baker, Washington is a hydrology monitoring site where water is collected and measured for chemicals that may signal volcanic unrest.

Lahar deposit cross section in the Trout Lake lowland, which originated from Mount Adams. Thickness of deposit is about 2.5 m (8 ft).

Remnant of Villard Glacier is in cirque below. Thick summit lava flow makes up "Glisan Pinnacle," which overlies hundreds of thin rubbly lava flows that are intercalated with red-oxidized agglutinate and scoria falls exposed on 800-m- (2600-ft-) high face below. Flows that form ridge at upper right are thicker than those on most of edifice.

Three Sisters annotated photograph viewed from south to North from Broken Top, Oregon.

Dome building episode from 2004-2008 at Mount St. Helens can be observed and measured with these two digital elevation models (DEMs) developed before and after the eruptive episode.

Volcanic mudflows (lahars and debris flows) occur more commonly after a landscape has been covered by loose volcanic material. Sign on the slopes of Rabaul, Papua New Guinea.

Volcano Evacuation Route sign along a roadway in Washington State.

Distribution of young volcanic rocks by age in Haleakalā Crater, Maui.

Some of the large ballistic blocks from the Kīlauea eruption of 1924 later became visitor attractions. Many of these blocks remain in place today as evidence of the forces unleashed at Kīlauea during the eruption of 1924.

Top: Photograph of the SO2 camera installation when scientists tested the radio link to the Hawaiian Volcano Observatory (HVO). The camera is aimed at the plume emitting from the Overlook Crater, about 1.4 km away. Under typical trade wind conditions, the plume is blown to the southwest, thus moving from right to left in the imagery.

Seismic station locations (red triangles) on the Island of Hawai‘i and across the State of Hawaii (inset).

Earthquakes near the Island of Hawai‘i between 1970-2006 with magnitude greater than 2.5. A (top left): locations of shallow earthquakes 0-22 km (0-14 mi) depth. B (top right): locations of deep earthquakes 22-55 km depth (14-34 mi). Bottom (C): cross section showing the depths of earthquakes in the rectangle in figure B.