USGS Volcano Hazards Program Volcano Update

HVO update page and observatory web site

Activity Summary: The eruption continued at two locations. The summit tiltmeter network recorded weak inflationary tilt and the summit lava-lake level rose a few more meters. At the middle east rift zone, the Pu`u `O`o tiltmeter recorded minor fluctuations while the vent continued feeding the Kahauale`a 2 lava flow which remained active and burning forest to the northeast. Gas emissions remained elevated.

Recent Observations at Kilauea summit: The summit tiltmeters recorded weak inflationary tilt and the lava-lake level continued rising to an estimated 35 m (115 ft) below the floor of Halema`uma`u by this morning. Gas emissions continued to be elevated: during the week of 01/01-01/07, the summit SO2 emission rate varied between 3,300 and 5,800 tonnes/day (see caveat below); however, no reliable emission rate measurements could be made over the past several weeks due to the absence of moderate trade-winds except for a few brief periods during which the emission rates were measured at values within the range of 1,000 to 6,000 t/d representing conditions of no spattering to spattering lake conditions. A small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the circulating lava lake) was carried out of the vent within the gas plume and deposited onto nearby surfaces.

Seismic tremor levels were low with two dropouts. Thirty-one earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 4 within the Ka`oiki Pali area, 10 seismic events scattered beneath the summit caldera, 1 within the southwest rift zone, 1 well to the northeast of the summit caldera (area of Volcano Village), 6 within the upper east rift zone, 1 within the middle east rift zone (near Pu`u `O`o), and 8 on the south flank faults. GPS receivers spanning the summit caldera recorded changes mimicking the recent tilt changes after recording more than 2 cm of extension since early December, 2013; 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 sulfur-dioxide emission-rate measurement was 300 tonnes per day on January 29, 2014, from all east rift zone sources; emission rates typically ranged between 150 and 450 t/d since July 2012. GPS receivers on the north rim and south flank of Pu`u `O`o cone recorded fluctuations mimicking the tilt changes after recording about 2 cm of extension since mid-December 2013. The Pu`u `O`o eruption continued with no significant changes. Spatter cones on the floor of Pu`u `O`o crater displayed persistent glow with a small active lava pond within the collapsed northeast spatter cone (see images and video).

Recent Observations of the Kahauale`a 2 flow: The northeast spatter cone complex continued to feed the Kahauale`a 2 lava flow which reached 7.8 km (4.8 mi) northeast of Pu`u `O`o by mid-January before stalling. Recent surface flows have been active as small scattered breakouts behind the flow front. A satellite image of the flow field on Saturday, Feb. 15, showed that there has been little expansion of the Kahauale`a 2 flow field over the past few weeks, with most active breakouts back from the flow front and margins. On February 15, the active breakouts extended 7.2 km (4.5 mi) northeast of the vent on Pu`u `O`o mostly covering previously-erupted lava flows; however, clouds covered the area beyond this point and didn't allow clear views of any possible flow progress farther northeastward in the satellite image. Webcam views last night clearly showed multiple active breakouts and fires within the adjoining forest areas suggesting that the most recent DI events had little effect on Kahauale`a 2 flow activity. An overflight is planned for today.

In general, this slow-moving lava flow has made erratic progress over the past few months. Disruption of the flow front has occurred during strong DI deflation events when the lava supply abruptly dropped causing the front to stagnate. DI inflation and resumption of lava supply usually follow a few days later. Breakouts reappear well behind the stalled flow front and take some time to reach the front again. In this way, the flow front has not advanced more than 500 m (1,600 ft) since the first time it stalled in early November, 2013.

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 and the ocean entry ceased in August 20, 2013; the flow was dead by early November, 2013. 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. Active lava flows within forest can produce methane blasts that propel rocks and other debris into the air. All recently active lava flows are within Hawai`i Volcanoes National Park and adjacent State land managed by the Department of Land and Natural Resources or the Office of Hawaiian Affairs; the lava flows do not pose an imminent 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 - Most of the flow field is within the closed-access Kahauale'a Natural Area Reserve (NAR) or the Wao Kele o Puna Forest Reserve (DLNR, OHA) and can only be viewed from the air. Under favorable weather conditions at night, distant glow from the active flows 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

Sulfur Dioxide Emission Rate estimation caveat: Starting in 2014, we report the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed. For more on this reporting change, please read

Update in Common Alerting Protocol (CAP) format