USGS Volcano Hazards Program Volcano Update

HVO update page and observatory web site

Activity Summary: Eruption continued at two locations with little change in the past 24 hours. The summit tiltmeter network recorded continued DI deflationary tilt and the lava-lake level dropped almost 20 m. At the middle east rift zone, the Pu`u `O`o vent continued to feed the Kahauale`a 2 lava flow, although its activity may be waning as a result of the ongoing DI event. Gas emissions remained elevated.

Recent Observations at Kilauea summit: The summit tiltmeters continued recording DI deflationary tilt totaling more than 4 microradians by this morning. The lava-lake level has now dropped almost 20 m since the start of the DI deflation and it stabilized overnight at an estimated 63 m (207 ft) below the floor of Halema`uma`u; this is the deepest the lake surface has been in the vent cavity since early December 2013. 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 were made during the week of 01/08-01/14 due to the absence of moderate trade-winds. Although not measured this morning, a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the circulating lava lake) was probably carried out of the vent with the gas plume and deposited onto nearby surfaces.

Seismic tremor levels were low and variable with multiple dropouts. An unusually large number of forty-one earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 13 on south flank faults, 9 beneath Halema`uma`u Crater (some of these events are probably the seismic expression of lava veneer spalling off the vent cavity walls and falling into the lava lake), 8 beneath the northern portion of the summit caldera, 6 within the upper east rift zone (including 4 deep earthquakes), and 5 south of Halema`uma`u. GPS receivers spanning the summit caldera recorded line length changes that mimicked the short-term trends in tilt (mostly DI tilt events) and about 1 cm of extension over the past month; 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 more than 1.5 microradians of DI deflationary tilt by this morning (start was delayed 5.5 hrs after summit). The most recent sulfur-dioxide emission-rate measurement was 250 tonnes per day on December 24, 2013, 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 minor fluctuations over weak extension (more than 1 cm over the past month and more than 25 cm since April 2010).

The Pu`u `O`o eruption continued without significant change. Spatter cones on the floor of Pu`u `O`o crater displayed persistent bright glow; just before 9 pm last night, the north side of the northeast spatter cone collapsed, possibly due to lower lava levels as a result of the ongoing DI deflation event. Despite the collapse, the northeast spatter cone continued to feed the Kahauale`a 2 lava flow through the early morning hours before weather blocked webcam views; the Kahauale`a 2 flow still extends 7.5 km (4.7 mi) northeast of Pu`u `O`o (per 01/17 satellite image) although the front now appears to be spreading to the north slightly while it advances to the northeast. When weather permits, views of the distant flow front from the PNcam and R3cam (working intermittently) showed small breakouts at night and burning forest during the day in several spots; a few views of the flow front this morning between 6:30 and 7:30 am suggest that flow front activity has diminished greatly, probably as a result of the ongoing DI deflation.

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