USGS Volcano Hazards Program Volcano Update

HVO update page and observatory web site

Activity Summary: Kilauea continued to erupt at two locations: At the summit, tilt and lava lake levels were stable. At Pu`u `O`o, glow was visible from the usual source with two overflows from the northeast spatter cone and a small lava flow from one of the south spatter cones within the crater. Lava flows were active on the coastal plain, and lava is entering the ocean near Kupapa`u. Seismic tremor levels were low and gas emissions were elevated.

Recent Observations at Kilauea summit: The summit tiltmeter network recorded minor variations but no net inflation or deflation and the lava lake level remained high but below the inner ledge. The most recent (preliminary) sulfur dioxide emission rate measurement was 1,100 tonnes/day on December 12, 2012. A small amount of ash-sized tephra (fresh spatter bits and Pele's hair) was likely carried out of the vent in the gas plume and deposited on nearby surfaces. The County Kalapana Viewing Area crew reported a new breakout at the top of the pali last night which may rob supply from the coastal plain flows if it continues.

Seismic tremor levels are at low values. Five earthquakes were strong enough to be located beneath Kilauea: 2 beneath the Ka`oiki Pali area west of the summit caldera, 1 within the upper east rift zone, 1 north of the middle east rift zone, and 1 on south flank faults. The summit network of GPS receivers recorded very weak extension across the caldera.

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 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 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: a tiny western branch that was not visibly active last night, and a larger eastern branch with scattered surface activity extending from near the pali to the coast east of the easternmost boundary of Hawai`i Volcanoes National Park. An ocean entry marked by a weak and variable plume continued near Kupapa`u.

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.

At Pu`u `O`o, lava levels appeared to be high with a large overflow of the northeast spatter cone that started early yesterday morning and finished by mid-morning yesterday accompanied by a brief lava flow from the southwestern spatter cone; a second overflow from the northeast spatter cone occurred last night; glow could be seen from several locations on the crater floor.

The tiltmeter on the north flank of Pu`u `O`o cone recorded no significant ground changes; any weak inflation signal was correlated with rainfall and therefore suspect. Seismic tremor levels near Pu`u `O`o remain low. The most recent (preliminary) sulfur dioxide emission rate measurement was 230 tonnes/day on December 12, 2012, from all east rift zone sources. GPS receivers on either side of the crater recorded continued weak extension.

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

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