Images

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.

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.

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.

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.

Mount Bachelor seen from South Sister across Sparks Lake. One of the "Devils Chain" domes visible in lower image foreground. Oregon

Adam Mosbrucker tests equipment (Acoustic Doppler Current Profiler, survey-grade RTK-GPS and a map-grade GPS) in preparation for a lake bottom survey.

Quaternary volcanic rocks are shown in black, and main centers are labeled. Chilliwack batholith and Pemberton belt represent Oligocene– Miocene arc 20–50 km inboard of Quaternary Garibaldi arc. Dashed line surrounding Puget Lowland shows maximum extent of Puget lobe of Cordilleran Ice Sheet during the last glaciation.

Crater Lake, Oregon simplified hazards map showing potential impact area for ground-based hazards during a volcanic event.

Mount Adams viewed from the southeast in Klickitat Valley, Washington.

Map of horizontal displacement vectors for Global Positioning System (GPS) stations in and around Mount St. Helens. Blue arrows show the direction and magnitude of horizontal movement, as measured at the GPS station from 2008-2014. The total horizontal displacement is indicated in millimeters (mm) and inches (in).

The Uwekahuna WT (water-tube) instrument is still measured today, providing one of the longest records of deformation for any volcano. The tiltmeter is read by looking into the portal on each pot and adjusting the sight until two pins appear to touch.

Big Pine Volcanic Field, California, from southwest cinder cone, with US Route 395 and Owens River in view