Images

USGS Hawaiian Volcano Observatory scientists are closely monitoring recent signs of unrest on Mauna Loa, the largest active volcano on Earth. In this 1985 aerial photo, Mauna Loa looms above Kīlauea Volcano's summit caldera (left center) and nearly obscures Hualālai in the far distance (upper right). USGS photo.

After 25 years of slumber, Mauna Loa woke with a spectacular, but short-lived, eruption that began just before midnight on July 5. Lava fountains soon erupted from fissures extending across the length of Moku‘āweoweo, Mauna Loa's summit caldera, and into the upper ends of the volcano's northeast and southwest rift zones.

On June 1, 1950, a 2.4-km (1.5 mi) long fissure erupted high on Mauna Loa's Southwest Rift Zone at 9:04 p.m. Minutes later, the roar of lava fountains could be heard up to 24 km (15 mi) away.

The four-tiered USGS Volcanic Activity Alert-Notification System uses Volcano Alert Level terms and Aviation Color Codes to inform people about a volcano's status and potential volcanic ash hazards. For more information about this system, please see http://pubs.usgs.gov/fs/2006/3139/.

TOP: Mauna Loa weekly earthquake rates between 2010 and September 17, 2015. Blue bars indicate the number of earthquakes that were located by the USGS Hawaiian Volcano Observatory seismic network. Earthquakes of all magnitudes are plotted. Subtle increases in earthquake rates started in mid-2013, while more obvious changes in rates started in 2014.

USGS scientist Brad Slaugh measures streamflow following a flash flood event in Hildale, Utah.

USGS scientist Brad Slaugh taking measurements following a flash flood event in Hildale, Utah.

USGS scientist Brad Slaugh measures streamflow following a flash flood event in Hildale, Utah.

USGS crews are taking measurements following a flash flood event in Hildale, Utah.

There has been no significant change on the flow field northeast of Pu‘u ‘Ō‘ō, and some of the active flows continue to creep into the forest along the north edge of the flow field, as seen here, looking roughly northwest. Activity has been remarkably stable and consistent, with no overall advancement of the flows, for the last several weeks.

This map overlays a georeferenced thermal image mosaic onto a map of the flow field to show the distribution of active and recently active breakouts. The thermal images were collected during a helicopter overflight of the flow field on September 11. The June 27th flow is outlined in green to highlight the current flow margin.

Photo of Pu‘u ‘Ō‘ō west of the crater, looking north-northwest. The west edge of the crater is to the right. The western pit, with the lava pond, is just above and left of center. Notice the vaguely arcuate line of fume that wraps from the south edge of the crater, around the western pit, and back to the northwest edge of the crater in the background.

View of Pu‘u ‘Ō‘ō crater, looking northwest. The floor of the crater was paved in late August by lava that erupted from a vent at the northeast edge of the crater, which is the heavily fuming area to the right.

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 August 26 is shown in pink, while widening and advancement of the flow as of September 11 is shown in red. The yellow lines show the active lava tube system.

This bathymetric grid represents approximately 3900 kilometers of bathymetric data collected in 2014. These data were collected using a dual-head R2Sonic 2024 multibeam echosounder (MBES) by Alpine Ocean Seismic Survey, Inc., during USGS field activity 2014-072-FA.

George Kojima, circa 1959, analyzing volcanic gases using the Hawaiian Volcano Observatory's state-of-the-art (at the time) mass spectrometer. USGS photo.

This satellite image was captured on Wednesday, September 2, by the Advanced Land Imager instrument onboard NASA's Earth Observing 1 satellite. The image is provided courtesy of NASA's Jet Propulsion Laboratory. Although this is a false-color image, the color map has been chosen to mimic what the human eye would expect to see.

A time-averaged image from Duck, North Carolina, on September 1, 2015. Dark bands extending offshore from the beach show the rip current channels.

A large breakout from the lava tube on the north side of Pu‘u ‘Ō‘ō yesterday (August 27) formed a large channelized flow, but it did not last long. The activity died in the evening, the same day, and traveled only about 500 m (about 550 yards).

As magma rises toward Earth's surface, gases dissolved in the molten rock bubble out and escape through surface vents called fumaroles. HVO established sensors atop Mauna Loa in late 2005 to continuously monitor the concentration of carbon dioxide and sulfur dioxide gases and fumarole temperature within Moku‘āweoweo, the summit caldera.

Yesterday's lava flows in Pu‘u ‘Ō‘ō erupted from a vent at the northeast edge of the crater and added a new layer to the crater floor. This photograph looks northeast across the relatively smooth crater floor toward the vent that erupted, which is a spatter cone that appears as a faintly visible mound in the fume in the background.