USGS Volcano Hazards Program Volcano Update

HVO update page and observatory web site

Activity Summary: Summit deflation began overnight but the lava lake level remained steady with minor fluctuation. Seismic activity decreased but remained elevated in the upper east rift zone. At Pu`u `O`o, lava flows issued from the north floor spatter cone and the lava lake in the NE pit remained active. Lava flows southeast of Pu`u `O`o continued to be weakly active on the coastal plain. Seismic tremor levels were low, and gas emissions were elevated.

Recent Observations at Kilauea summit: The summit tiltmeter network recorded slowing inflation yesterday that smoothly turned into deflation by midnight. The summit lava lake level showed minor fluctuations but remained fairly steady and did not drop since midnight.

The most recent (preliminary) sulfur dioxide emission rate measurement was 500 tonnes/day on October 31, 2012; this value is typical of measurements made between rise/fall events and constitutes a background level of emissions. Although not measured today, a small amount of ash-sized tephra (including Pele's hair and some fresh spatter bits) was probably carried out of the vent in the gas plume and deposited on nearby surfaces.

The GPS network continued recording extension across the summit caldera at the rate of about 1 cm/wk since the beginning of October. Seismic tremor levels increased slightly and summit and upper east rift zone seismicity decreased but remained elevated. Thirty-seven earthquakes were strong enough to be located beneath Kilauea mostly within the upper east rift zone: 7 beneath the west edge of the summit caldera, 6 within the seismic southwest rift zone south of the summit caldera, 1 deep quake beneath the lower southwest rift zone, 18 within the upper east rift zone, and 5 on south flank faults. Most of the upper east rift zone quakes were located between Keanakako`i and Puhimau Craters.

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 again dropped 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. 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: Surface flows continued weak activity in a collection of lobes about 1 km (0.6 mi) wide) within the abandoned Royal Gardens subdivision (see images), with flows slowly extending seaward across the coastal plain but still probably more than 1 km (0.6 mi) from the coast based on webcam observations.

At Pu`u `O`o, activity remained at moderate levels. A small lava flow issued from the spatter cone on the northern part of the crater floor yesterday evening followed by a larger effusion just after 11 pm last night. The perched lava lake within the northeastern pit remained active. The tiltmeter on the north flank of Pu`u `O`o cone recorded minor inflation with a small daily drop around noon and an abrupt, but small, drop about 11:15 pm that was probably related to the large lava flow already mentioned. GPS receivers spanning the Pu`u `O`o crater recorded extension rates of about 0.5 cm/wk through most of October followed by a small contraction and no change over the past few days mimicking general tilt trends. Seismic tremor levels near Pu`u `O`o were low. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on October 31, 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. Since late December, the flows have remained intermittently active on the pali and the coastal plain but have not entered the ocean. 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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