Images

This volcanic-gas monitoring station installed at Mount St. Helens consists of weather monitoring equipment and sensors for measuring the concentrations of water vapor (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), and hydrogen sulfide (H2S) in volcanic gas plumes.

Sediment-laden White River 11 km downstream of the OR35 bridge. Heavy rains resulted in high-sediment loads within this river, which drains Mount Hood, Oregon.

Mount Hood Spectrograms for August 21, 2015.

View from the OR35 bridge over the White River looking downstream. Glistening areas are deposits from recent debris flows.

The overflow of Halema‘uma‘u Crater on February 23, 1918. Photo by T.A. Jaggar from the HVO Record Book courtesy of Bishop Museum.

USGS Hawaiian Volcano Observatory geophysicist Ingrid Johanson measures gravity with a gravimeter on the slope of Mauna Loa with Mauna Kea visible in the background. USGS photo.

Dr. Seth Moran at USGS-Cascades Volcano Observatory

This small-scale map shows Kīlauea's active East Rift Zone lava flow in relation to the eastern part of the Island of Hawai‘i. The area of the flow on July 23 is shown in pink, while widening and advancement of the flow as of August 5 is shown in red.

This map shows recent changes to Kīlauea's active East Rift Zone lava flow field. The area of the flow on July 23 is shown in pink, while widening and advancement of the flow as of August 5 is shown in red. The yellow lines show the active lava tube system. Pu‘u ‘Ō‘ō lava flows erupted prior to June 27, 2014, are shown in gray.

Volcanic ash deposit at base of Uwēkahuna Bluff below Jaggar Museum. Photo by T.A. Jaggar on July 29, 1913. Ash deposit buried by lava flow in 1919. Standing man is circled. From HVO Record Book courtesy of Bishop Museum.

Lava flows are scattered across a broad area extending from about 3 to 8 km (2-5 mi) northeast of Pu‘u ‘Ō‘ō. The active flows start just above the horizontal mid-line of the photo, but cannot be picked out easily within the broader inactive flow field due to their distance away in this photo.

The pit west of the Pu‘u ‘Ō‘ō crater, shown here, is overhung on most sides and may continue to widen with time. The lava pond inside is relatively placid, appearing as a black surface, usually with a few tiny spattering areas along the edge.

An HVO scientist collects a molten lava sample using a rock hammer. Molten lava on the flow field for the last several months has had a temperature usually around 1,140 ?ºC, or just under 2,100 ?ºF, when collected and can blister exposed skin when this close.

High aerial view of Pu‘u ‘Ō‘ō, looking south-southwest. The current crater at Pu‘u ‘Ō‘ō is about 280 m (~920 ft) long and 230 m (~755 ft) wide, with a depth of about 25 m (~82 ft). To the west of the crater is another pit 49 m (~161 ft) across that contains a small lava pond.

Raymond and Whitcomb party "making lava specimens" at Kīlauea in 1893. Photograph by J.J. Williams from the HVO photo archives.

Views into Pu‘u ‘Ō‘ō's current crater are often hampered by fume. To overcome this, HVO uses thermal cameras that detect heat and are better able to 'see' through the fume. This image mosaic compares the Pu‘u ‘Ō‘ō thermal webcamera's view with an oblique aerial photograph to show what the thermal camera is looking at.

The summit lava lake today was at a relatively low level, about 65 meters (210 feet) below the Overlook crater rim, associated with summit deflation. Spattering was active along the lake margins. This photograph shows overflows from April and May (dark lava in bottom portion of photograph) covering the floor of Halema‘uma‘u Crater.

Pele's hair covers the roadside along Crater Rim Drive, next to the Halema‘uma‘u parking lot, in an area of Hawai‘i Volcanoes National Park closed to the public due to proximity to the summit lava lake. The Pele's hair (long strand of volcanic glass) is emitted from the lava lake and carried upwards by the rising gas plume, and then drifts downwind.

This map overlays a georeferenced thermal image mosaic onto the flow field change map to show the distribution of active and recently active breakouts. The thermal images were collected during a helicopter overflight of the flow field on July 23. The June 27th flow is outlined in green to highlight the flow margin. The yellow line is the active lava tube.

An HVO geologist collects a sample of lava, quenching it in a bucket of water. Chemical analysis of the lava provides insight into changes in the magma plumbing system.

A closer look at the north margin of the June 27th lava flow, where breakouts are active at the forest boundary.