USGS Volcano Hazards Program Volcano Update

HVO update page and observatory web site

Activity Summary: Eruption continues with little change. Summit tilt and the lava lake level fluctuated minor amounts but remained fairly steady at the summit. At the middle east rift zone, the Kahauale`a II lava continued burning forest to the north. Southeast of Pu`u `O`o, the Peace Day flow had minor active breakouts at the base of the pali and on the coastal plain. Most of the flow remained within its lava tube until reaching the ocean on both the east and west sides of the Hawai`i Volcanoes National Park boundary. Gas emissions remained elevated.

Recent Observations at Kilauea summit: At the summit, tiltmeters recorded minor fluctuations - a very weak inflationary trend continued. The summit lava lake level fluctuated and remained about 45 m (150 ft) below the Halema`uma`u Crater floor. The most recent sulfur dioxide emission rate measurement was 700 t/d on June 21, 2013; this value is a minimum because the data were acquired close to the vent where the plume is most dense and challenging to fully characterize. Although not measured this morning, a very small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair) was likely carried out of the vent by the plume and deposited onto nearby surfaces.

Seismic tremor levels were low suggesting spattering and gas emissions were nearly continuous. Ten earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours - 1 within the Ka`oiki Pali area, 2 south of the summit caldera, 3 deep quakes beneath the upper east rift zone, 1 well north of the middle east rift zone, and 3 on south flank faults. The recent extension recorded by GPS receivers spanning the summit caldera stalled over the past few days.

Background: The summit lava lake is within a cylindrical vent with a diameter of ~160 m (520 ft) and nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level has varied from about 25 m to more than 200 m (out of sight) below the floor of Halema`uma`u Crater. The vent has been mostly active since opening with a small explosive event on March 19, 2008. The surface level of the lava lake has remained mostly below the inner ledge (~31 m or 100 ft below the floor of Halema`uma`u Crater on October 29, 2012) and has risen above and flooded the ledge in October 2012 and January 2013 before receding to greater depths. The lake level responds to summit tilt changes with the lake receding during deflation and rising during inflation.

Recent Observations at the middle east rift zone vents: The tiltmeter at Pu`u `O`o cone recorded fluctuations over a weak inflationary trend that may be enhanced by rainfall. The GPS line length from the north rim to the south base of Pu`u `O`o cone showed fluctuations without a longer-term trend since mid-May. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on June 17, 2013, from all east rift zone sources; these values have ranged between 150 and 450 t/d in 2013; measurements are made at a greater distance from the sources where the plume is more easily characterized.

Spatter cones on the crater floor of Pu`u `O`o showed their typical incandescence and the northeast spatter cone continued to feed the Kahauale`a II lava flow north of Pu`u `O`o; the June-18 breakout from the Kahauale`a II lava tube high on the NE flank of Pu`u `O`o cone continued to advanced northward over the Kahauale`a II flow. Using a combination of satellite imagery and older mapping on the ground, the most distant front of the Kahaulae`a flow was still about 2.5 km (1.6 mi) due north of Pu`u `O`o, expanding a bit to the east, and still burning forest at the north edge of Pu`u `O`o's 1983-1986 `a`a flow field. A second active front was still about 1.9 km (1.2 mi) NNW of Pu`u `O`o, expanding to the west, and slowly advancing and also burning the edge of the forest. PNcam views overnight recorded continued activity at the flow fronts burning forest north of Pu`u `O`o.

Southeast of Pu`u `O`o, the Peace Day flow hosted new active breakouts at the base of the pali and continuing scattered breakouts about mid-way across the coastal plain near the Hawai`i Volcanoes National Park boundary. Most of the Peace Day flow, however, remained in lava tubes that empty into the ocean in two places - a main entry point, producing a persistent gas plume just east of the Hawai`i Volcanoes National Park boundary and a smaller entry point producing a smaller, intermittent gas plume just inside the National Park.

HAZARD ALERT: Lava entering the ocean builds lava deltas. The lava delta and adjacent areas are some of the most hazardous areas on the flow field. Frequent delta/bench collapses give little warning, can produce explosions capable of throwing both dense and molten rocks hundreds of meters (yards) in all directions (inland as well as out to sea), and can produce damaging local waves. The steam plume produced by lava entering the ocean contains fine lava fragments and an assortment of acid droplets that can be harmful to your health. The rapidly changing conditions near the ocean entry have been responsible for many injuries and a few deaths.

Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and continued with few interruptions at Pu`u `O`o Cone, or temporarily from vents within a few kilometers to the east or west. A fissure eruption on the upper east flank of Pu`u `O`o Cone on Sept. 21, 2011, drained the lava lakes and fed a lava flow (Peace Day flow) that advanced southeast through the abandoned Royal Gardens subdivision to the ocean within Hawai`i Volcanoes National Park in early December 2011. Since late December 2011, the flows have remained intermittently active on the pali and the coastal plain and finally re-entered the ocean starting on November 24, 2012. The Kahauale`a flow, which started from the spatter cone/lava lake at the northeast edge of the Pu`u `O`o crater floor in mid-January, 2013, was dead by late April, but a new flow (Kahauale`a II) became active in the same general area in early May . In general, activity waxes with inflation and wanes with deflation.

Hazard Summary: East rift vents and flow field - near-vent areas could erupt or collapse without warning with spatter and/or ash being wafted within the gas plume; potentially-lethal concentrations of sulfur dioxide gas may be present within 1 km downwind of vent areas. All recently active lava flows are within Hawai`i Volcanoes National Park, adjacent State land managed by the Department of Land and Natural Resources, and private property; the lava flows do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. Lava deltas, which can collapse into the ocean without warning, are extremely hazardous and should be avoided (see HAZARD ALERT above). Kilauea Crater - ash and Pele's hair can be carried several kilometers downwind; potentially-lethal concentrations of sulfur dioxide can be present within 1 km downwind.

Viewing Summary: East rift zone flow field - Most of the flow field is within the closed-access Kahauale'a Natural Area Reserve (NAR) and the abandoned Royal Gardens subdivision and can only be viewed from the air. A small part of the western flow field near the coast in within Hawai`i Volcanoes National Park (see below for access info). Under favorable weather conditions, active flows-when present-can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093). Pu`u `O`o Cone and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; Park access and viewing information can be found at

Update in Common Alerting Protocol (CAP) format