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, there was no change in lava lake level. At Pu`u `O`o, glow was visible from the usual sources, with several short-lived flows erupting from one of the spatter cones on the southeastern side of the crater floor. 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 no significant changes before and after a brief and abrupt deflation at about 1:30 am this morning; the deflation was not coincident with an earthquake nor with any change in lava lake level. The lava lake was relatively steady and showed no net change in level over the past several days. The most recent (preliminary) sulfur dioxide emission rate measurement was 1,000 tonnes/day on December 6, 2012, though measurement conditions were not ideal. A small amount of ash-sized tephra (including fresh spatter bits and Pele's hair) was likely carried out of the vent in the gas plume and deposited on nearby surfaces.

Seismic tremor levels are at low values. Eleven earthquakes were strong enough to be located beneath Kilauea: 4 in the upper east rift, 1 within the upper southwest rift zone, 3 beneath the southern summit caldera, and 3 on south flank faults.

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, 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, with lava entering the water in at least two different spots.

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, glow could be seen emanating from several locations on the crater floor: the spatter cone on the northwest side of the crater beneath the webcams, the northeastern lava lake (now mostly hidden beneath a spatter cone), and both spatter cones on the southeastern part of the floor. Small, short-lived flows erupted from the western-most of the two southeasterly spatter cones five times between noon yesterday and 7 am this morning; a small flow issued from the northeastern lava lake/spatter cone early yesterday morning.

The tiltmeter on the north flank of Pu`u `O`o cone recorded mostly rain-induced inflation with small tilt jumps accompanying each of the small flows mentioned above. Seismic tremor levels near Pu`u `O`o remain low. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on November 28, 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