Images

Hualālai Volcano (center) above Kīholo Bay on Hawai‘i Island's West Coast is flanked by lava flow erupted from the volcano around 1800 (right) and 1859 Mauna Loa flow (left).

CalVO scientist Tom Sisson studies a lava flow in the Harrat Rahat Volcanic Field in Saudi Arabia for an international collaboration with the Saudi Geological Survey to conduct a seismic and volcanic hazard assessment for the volcanic field.

Simulated fractures and subsidence above a widening dike (dark area at bottom) were generated in a small-scale model using a box filled with flour, sugar, and corn meal. The simulated dike (tip is dark area bottom center of photograph) consisted of two linoleum sheets taped together.

CalVO staff assembled in the Rambo Auditorium, Menlo Park, CA

Guardian Geyser and Norris Geyser Basin, Yellowstone National Park.

Locations (Lat, Long, Depth) of January 17, 2010, earthquake swarm on Madison Plateau, Yellowstone National Park.

Tiltmeters allowed 24-hour monitoring as the information was telemetered back to CVO. Other instruments such as displacement meters for measuring cracks, seismometers for measuring earthquakes, gas sensors for measuring gas concentrations, and magnetometers for measuring the magnetic field, were also used for 24-hour monitoring.

Mammoth Hot Springs at Yellowstone National Park, Wyoming.

Magma forms above the subducting slab of oceanic crust and accumulates at the base of Earth's rigid crust before collecting in a storage zone 13 km (8 mi) beneath the volcano prior to eruption.

Mount Baker's crater lake in 1976 formed due to glacial and snow melt as a result of increased heat from magma beneath the surface. Fumarole on left ejecting gas at a velocity of 268 kph (167 mph).

Brimstone Basin, Yellowstone, aerial photo with overlay of two types of altered ground (light blue and pale pink shading) and locations of gas measurements (red dots). 2012 study

Geologic Hazards at Volcanoes (click for larger version)

Mount Scott Lookout seismic and GPS volcano monitoring station, view from the southwest. Near Crater Lake, Oregon.

Deformation monitoring equipment—GPS antenna maintenance on south side of Crater Lake National Park Boathouse on Wizard Island. Oregon

Oblique aerial photograph of source areas and runout paths of some of the devastating debris flows that were responsible for more than 20,000 fatalities in Vargas state, Venezuela, December 1999.

Lava-flow hazard zones map, Island of Hawai‘i. See Full Map for complete legend.

Sampling gas and taking temperature measurements from a fumarole at the summit of Mount Rainier, Washington.

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.