USGS Volcano Hazards Program Volcano Update

HVO update page and observatory web site

Activity Summary for past 24 hours: DI deflation started late last night and the summit lava lake level dropped afterward. Glow was visible at Pu`u `O`o from spatter cones on the northeast and southeast edges of the floor and from the upper tube system on the east flank; the public Pu`u `O`o webcams were not operational. Active surface flows were visible at the top of the pali southeast of Pu`u `O`o. There were no active flows on the coastal plain or entering the ocean. Seismic tremor levels were low and gas emissions were elevated.

Past 24 hours at Kilauea summit: DI deflation started at 11:15 pm last night and the lava lake started to drop as expected. Since mid-October 2011, the summit GPS network recorded continued weak extension. Seismic tremor levels were low. The most recent (preliminary) sulfur dioxide emission rate measurement was 1,000 tonnes/day on February 28, 2012. Slightly larger amounts of ash-sized tephra were wafted within the gas plume and deposited on nearby, downwind surfaces over the weekend, probably as a result of the frequent high stands and the accompanying spattering afterward.

Six earthquakes were strong enough to be located beneath Kilauea: three beneath the Ka`oiki Pali, one within the southwest rift zone, one within the east rift zone, and one on south flank faults.

Background: The summit lava lake is deep within a ~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 70 m to more than 150 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. Most recently, the lava level of the lake has remained below an inner ledge (75 m or 250 ft below the floor of Halema`uma`u Crater) and responded to summit tilt changes with the lake receding during deflation and rising during inflation.

Past 24 hours at the middle east rift zone vents: Within Pu`u `O`o crater, glow could be seen from a small collapse pit and spatter cone on the northeast edge and spatter cone on the southeast edge of the floor; glow could also be seen from the uppermost tube system on the east flank of Pu`u `O`o cone; the public Webcams viewing Pu`u `O`o crater should be operational late this week. Seismic tremor levels near Pu`u `O`o were low. The tiltmeter on the north flank of Pu`u `O`o cone recorded continued inflation with possible DI deflation starting at 6:30 am this morning. GPS receivers on opposite sides of the cone continued to show neither extension nor contraction. The most recent (preliminary) sulfur dioxide emission rate measurement was 600 tonnes/day on February 17, 2012, from all east rift zone sources.

The east and west lobes have stalled at the base of the pali but remain active near the top of the pali probably above 1,000 ft elevation. The leading edge of the flows are around 7 km (4 mi) southeast of Pu`u `O`o. There are no active flows on the coastal plain or entering the ocean.

Background: The eruption in Kilauea's middle east rift zone started with a fissure eruption on January 3, 1983, and has continued since at Pu`u `O`o Cone, or from vents within a few kilometers to the east or west, with few interruptions. In early August, 2011, the Pu`u `O`o crater floor collapsed to a depth of about 75 m (245 ft) below the east rim of the crater as lava burst from vents on the lower west flank of the cone. A DI tilt event several days later cut off supply to Pu`u `O`o and the west flank vents; lava reappeared in Pu`u `O`o Crater on August 21st and filled it to overflowing. 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. The ocean entry has been inactive since late December but the flows have remained intermittently active above or on the pali. 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 - There are minor active lava flows within the closed-access Kahauale'a Natural Area Reserve (NAR) and the evacuated Royal Gardens subdivision, which can only be viewed from the air. Under favorable weather conditions, the flows can be seen from the County Viewing Area at Kalapana and in the Holei webcam. Pu`u `O`o Cone, the (inactive) West Ka`ili`ili lava ocean entry, and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; access and viewing information can be found at

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