USGS Volcano Hazards Program Volcano Update


HVO update page and observatory web site


Activity Summary: Eruption continued at two locations: At the summit, weak inflation and lava lake level fluctuations continued. At Pu`u `O`o, a small lava flow overflowed from the lava lake last night and glow was visible from the usual sources. Lava flows on the coastal plain were active but not entering the ocean. Seismic tremor levels were low, and gas emissions were elevated.

Recent Observations at Kilauea summit: It's a less voggy morning than yesterday. The summit tiltmeter network recorded continued weak inflation with a small deflation at 8:24 am yesterday; this minor morning deflation does not correspond with any other behavior at the summit. The lava lake level again slowly fluctuated. The most recent (preliminary) sulfur dioxide emission rate measurement was 500 tonnes/day on November 26, 2012; this value is at the low end of measurements made between rise/fall events but still constitutes a background level of emissions. A small amount of ash-sized tephra (including fresh spatter bits and Pele's hair) was carried out of the vent in the gas plume and deposited on nearby surfaces.

Seismic tremor levels remained steady at low values. Ten earthquakes were strong enough to be located beneath Kilauea: 2 deep quakes in the Ka`oiki Pali area, 3 within the upper east rift zone, and 5 on south flank faults including 2 earthquakes beneath the coast near Napu`uona`elemakule. The GPS network recorded neither net extension nor contraction across the summit caldera since November 2.

Background: The summit lava lake is deep within an ~160 m (520 ft) diameter cylindrical vent with nearly vertical sides inset within the east wall and floor of Halema`uma`u Crater. Its level fluctuates from about 40 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 below the inner ledge (~31 m or 100 ft below the floor of Halema`uma`u Crater on October 29, 2012) and has not risen above and flooded the ledge since October 28, 2012. 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: Lava flows remained active in two branches on the coastal plain; the eastern branch remained active in patches all the way across the coastal plain to the coast east of the easternmost boundary of Hawai`i Volcanoes National Park but there was no gas plume visible from the ocean entry point yesterday or since sunrise this morning. A UHH Geology Department crew confirmed that there was no ocean entry and that active flows were present about 180 m (590 ft) from the coast.

HAZARD ALERT: Lava entering the ocean builds lava deltas. The lava delta and adjacent areas both inland and out to sea are some of the most hazardous areas on the flow field. Frequent delta/bench collapses give little warning, can produce hot rock falls inland and in the adjacent ocean, 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.

At Pu`u `O`o, a small amount of lava overflowed from the lava lake in the northeast part of the crater floor at about 6:30 pm last night. Glow could be seen from the spatter cone on the north edge and the lava lake at the northeast edge of the crater floor with weaker glow from both sources in the south part of the floor. The tiltmeter on the north flank of Pu`u `O`o cone recorded weak inflation with fluctuations; GPS receivers on opposite sides of the crater recorded a minor amount of extension since November 23 mimicking tilt. Seismic tremor levels near Pu`u `O`o were low. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on November 26, 2012, from all east rift zone sources.

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 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. 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 within the Royal Gardens subdivision; the lava flows do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. 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 - The active lava flows were within the closed-access Kahauale'a Natural Area Reserve (NAR) and the abandoned Royal Gardens subdivision and can only be viewed from the air. Under favorable weather conditions, these flows can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093). Pu`u `O`o Cone, the strip of coastal plain nearest the ocean, and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; Park access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.

Update in Common Alerting Protocol (CAP) format