USGS Volcano Hazards Program Volcano Update


HVO update page and observatory web site


Activity Summary: DI inflation and a rise of the summit lava lake started yesterday evening. At Pu`u `O`o, lava circulated in the east pit and appeared for several hours in the south pit; glowing spots were seen in the west pit; lava flows continued to advance southeast of Pu`u `O`o at the top of the pali. Seismic tremor levels were low. Gas emissions were elevated.

Recent Observations at Kilauea summit: The summit tiltmeters recorded the switch to DI inflation at 6 pm yesterday and the lava lake level rose with inflation. The most recent (preliminary) sulfur dioxide emission rate measurement was 600 tonnes/day on September 25, 2012; this value was within the range of baseline measurements made between rise/fall events. Very small amounts of ash-sized tephra (spatter bits and Pele's hair) were carried out of the vent in the gas plume and deposited on nearby surfaces.

Seismic tremor levels were low. Two earthquakes were strong enough to be located beneath Kilauea: 1 just west of the summit caldera and 1 within the upper east rift zone.

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 60 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 (60 m or 200 ft below the floor of Halema`uma`u Crater on May 9, 2012) and responded to summit tilt changes with the lake receding during deflation and rising during inflation.

Recent Observations at the middle east rift zone vents: Several flow lobes continued to be a growing presence in Mobile Cam 3 indicating active flows at the top of the pali within the abandoned Royal Gardens subdivision overnight; geologists on Tuesday's overflight confirmed that these lobes are still advancing at about 100 m (100 yards) per day; the flows were also reported visible last night from the County Viewing Area farther to the east in Kalapana.

The tiltmeter on the north flank of Pu`u `O`o cone recorded a false inflation as rain masked any real earth tilts. Seismic tremor levels near Pu`u `O`o have been decreasing slowly. The most recent (preliminary) sulfur dioxide emission rate measurement was 260 tonnes/day on September 24, 2012, from all east rift zone sources.

At Pu`u `O`o Crater, the lava continued to circulate in the east pit and lava appeared within the south pit several times between 10 am and 6 pm yesterday; glow was again seen from spots on the west edge of the crusted north pit. The glowing spot at the base of the southeast flank of Pu`u `O`o, marking a collapse in the roof of the lava tube feeding lava flows downslope, continued to glow brightly overnight.

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 new breakout 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, glow from these flows may be reflected in clouds which 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 http://www.nps.gov/havo/planyourvisit/lava2.htm.

Update in Common Alerting Protocol (CAP) format