USGS Volcano Hazards Program Volcano Update

HVO update page and observatory web site

Activity Summary: Eruption at two locations continued with no significant changes. Summit instruments recorded short-term stability and the lava lake level rose slightly. At the middle east rift zone, the Kahauale`a 2 lava flow was active as small scattered breakouts burning forest north of Pu`u `O`o. The Peace Day flow southeast of Pu`u `O`o, which hosted a single minor breakout above the pali, may no longer be active. Gas emissions remained elevated.

Recent Observations at Kilauea summit: Summit tiltmeters recorded only minor fluctuations. The lava lake level tracked the changes in tilt and was at a measured 45 m (148 ft) below the floor of Halema`uma`u Crater this morning. Gas emissions continued to be elevated: the most recent sulfur dioxide emission rate measurement was 700 t/d on October 28, 2013 - the higher value represents a period in which spattering activity and gas release from the lava lake were active; however, these values are minimums because the data were acquired close to the vent where the plume is most dense and challenging to fully characterize. A small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the spattering sinks) was carried out of the vent with the gas and deposited onto nearby surfaces.

Seismic tremor levels remained low with two short dropouts. Seven earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 2 deep quakes in the Koa`e Fault zone, 2 north of and within the middle east rift zone, and 3 on south flank faults. GPS receivers spanning the summit caldera recorded line length changes that mimicked the short-term changes in tilt (DI tilt events) over the past two weeks; the long-term, cross-caldera measurements indicate continued extension at a rate averaging 10 cm/yr (4 in/yr) since March, 2010.

Background: The summit lava lake is within a nearly-cylindrical vent cavity 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 generally 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 minor fluctuations. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on October 28, 2013, from all east rift zone sources; these values have ranged between 150 and 450 t/d in 2013 and are made at a greater distance from the sources where the plume is more easily characterized. GPS receivers on the north rim and south flank of Pu`u `O`o cone recorded minor fluctuations over weak extension (less than 1 cm over the past month) and brief contraction over the past week. The Pu`u `O`o vent primarily feeds the Kahauale`a 2 flow to the north; activity on the older Peace Day flow to the southeast is minor with only one, weakly active breakout above the pali.

Spatter cones on the north and south portion of the Pu`u `O`o crater floor displayed persistent glow while the northeast spatter cone continued to feed the Kahauale`a 2 lava flow extending 5.8 km (3.6 mi) to the north (mapped on 10/21). PNcam and ETcam views showed continued lava activity as small scattered breakouts at the northern extremities of two branches of the Kahauale`a 2 flow and a few spots of burning forest.

The Peace Day flow was weakly active above the pali. On Monday, October 21, HVO geologists mapped a small breakout from the Peace Day tube about 3 km (1.9 mi) southeast of Pu`u `O`o that had minor pahoehoe activity. Although several clear MODIS images were available in the past 24 hours, none included a distinct thermal anomaly in this area suggesting that the minor breakout southeast of Pu`u `O`o may no longer be active.

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. The flows stalled and re-entered the ocean starting on November 24, 2012 until activity started to decline, the ocean entry ceased in August 20, 2013, and, as of October 2013, activity lingers as a single small breakout above the pali. 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 (informally called Kahauale`a 2) 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. 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. Under favorable weather conditions, active flows-when present-can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093) and from the end of the Chain of Craters Road within Hawai`i Volcanoes National Park. 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

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