Images

Scattered breakouts persist northeast of Pu‘u ‘Ō‘ō, with no significant advancement over the past month. Today, the farthest active breakouts were 5.8 km (3.6 miles) from the vent on Pu‘u ‘Ō‘ō. Several small breakouts were burning vegetation along the north margin of the flow, at the forest boundary. This photo looks upslope, towards the vent.

The small lava pond in the western portion of Pu‘u ‘Ō‘ō Crater was at a higher level today compared to previous visits, and closer to the pit rim. A disruption in the pond created increased spattering and agitation during our observation period. For scale, the pond is about 25 meters (80 ft) in diameter.

A closer look at the spattering and agitation in the small lava pond in Pu‘u ‘Ō‘ō.

An HVO geologist approaches one of the small vents in Pu‘u ‘Ō‘ō Crater to obtain a spatter sample.

Layers of explosive deposits erupted from Kīlauea Volcano in 17th and 18th centuries are visible in a road cut just beyond the gate at Keanakāko‘i Crater. This section of Crater Rim Drive has been closed since 2008, when the still-erupting vent within Halema‘uma‘u Crater (middle, far right) first opened. USGS photo.

The top plot is the number of located earthquakes per week from the Pacific Northwest Seismic Network's catalog. The bottom plot shows the earthquake depths with time. Earthquakes are plotted as circles with the size of the circle corresponding to the magnitude of the earthquake (see legend).

Map view plot of earthquakes located by the Pacific Northwest Seismic Network from March 14, 2016 through May 4, 2016. Only high-quality locations are shown (8 or more observations with a 130 degree gap or less between observing stations).

Darryl Oliveira, speaking with Puna residents about Kīlauea Volcano's June 27th flow during a community meeting at Pāhoa High School on September 25, 2014. This lava flow threatened lower Puna District communities only a few weeks after Hurricane Iselle made landfall in the same area of Hawai‘i Island.

A comparison of the 1946 Stearns and MacDonald map (left) and the 1996 BIMP map, digitized in 2005 (right), shows how the understanding of Hawai‘i Island's geology advanced over half a century. The Geologic Map of the Island of Hawaii is available online at http://pubs.usgs.gov/ds/2005/144/.

Alaska Volcano Observatory scientist Mark Hansen working with Larsen Bay Mayor David Harmes on how the AVO-4 particulate monitor operates.

Red dots show updated locations and magnitudes of three earthquakes that occurred on or around the Islands of O‘ahu and Maui in late March and early April 2016, as revised by seismologists at the U.S. Geological Survey's Hawaiian Volcano Observatory.

One benefit of passing showers today at Kīlauea's summit was a double rainbow. Halema‘uma‘u Crater is at the right side of the photo, and the gas plume from the active lava lake can be seen drifting towards the southwest. At the far right edge of the image, visitors take in the view at Jaggar Overlook.

Mauna Loa's summit was cold and clear this morning while HVO scientists performed maintenance on the summit thermal camera and two seismic stations. A few faint steam sources were noted in the usual locations on the caldera floor.

Surface breakouts remain scattered northeast of Pu‘u ‘Ō‘ō, with a slight retreat in the reach of active breakouts since the last overflight on March 25. Today, the farthest active lava was 5.7 km (3.5 miles) from the vent on Pu‘u ‘Ō‘ō. Much of the activity was at the forest boundary, burning trees and creating numerous smoke plumes.

One of the more vigorous breakouts on the flow field today, producing a sheet of blue-glassy pāhoehoe.

Views were hampered today by sporadic downpours. Once the rain passed, areas of active breakouts were evident by the larger steam plumes coming from the surface (for example, at the top center of the photograph).

HVO geologist uses a laser rangefinder to measure the depth of the lava lake at the summit of Kīlauea in the Overlook crater. The lake level was about 58 m (190 ft) below the crater rim this afternoon. In recent days the lake level has dropped about 35 m (115 ft) as tiltmeters at the summit have recorded a larger than usual deflationary trend.

During the Mauna Loa 1950 eruption, three large, fast-moving lava flows advanced down the west flank of the volcano, each crossing the main highway before reaching the ocean. The Ka‘apuna flow, shown here, traveled from the Southwest Rift Zone vent (7,800 ft elevation) to the coast in just 17 hours, creating a huge steam plume as lava flowed into the sea.

Photomicrograph of gabbroic inclusion in Ogres Brow basaltic andesite. A rock thin section is created by gluing a small piece of rock onto a glass slide, then grinding it down to a thickness of 30 microns (the average human hair is about 100 microns in diameter) so that light shines through it when examined under the microscope.

Brian Shiro in the Wind River Range, Wyoming during a National Outdoor Leadership School expedition. Photo courtesy B. Shiro.

During the first few days of Mount St. Helen's earthquake swarm in March 2016, the September Lobe monitoring station (located on the 1980-86 dome) was buried in deep snow and not transmitting data.