USGS Volcano Hazards Program Volcano Update


HVO update page and observatory web site


Activity Summary for past 24 hours: Minor back-to-back DI events continued and the summit lava lake level rose a bit yesterday before resuming its longer=term drop. At Pu`u `O`o: the east lava pond, and two glowing spots were visible. To the southeast, lava flows were active at the top of the pali and on the coastal plain without much forward progress; there was no ocean entry. Seismic tremor levels were generally low; gas emissions were elevated.

Past 24 hours at Kilauea summit: The summit tiltmeters recorded continued minor back-to-back DI tilt events (8 since June 13) superimposed on a weak deflationary trend. The lava lake level rose during yesterday's DI inflation, which was the largest since June 13 (1.4 microradians), and fell with deflation yesterday evening. The most recent (preliminary) sulfur dioxide emission rate measurement was 700 tonnes/day on June 19, 2012. In addition to gas, very small amounts of ash-sized tephra and Pele's hair were carried out of the vent in the gas plume and deposited on nearby surfaces.

The GPS network recorded weak long-term extension for the past few months with superimposed contraction and extension fluctuations corresponding to large DI tilt events. Seismic tremor levels were low. Eighteen earthquakes were strong enough to be located beneath Kilauea volcano: 2 deep quakes immediately west and south of the summit caldera, 6 very deep quakes northeast of the summit caldera, 4 within the upper east rift zone (clustered beneath Koko`olau Crater again), 1 within the middle east rift zone (beneath Pu`u `O`o), and 5 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 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.

Past 24 hours at the middle east rift zone vents: Lava flows were active at the top of the pali and on the coastal plain, where Webcam images showed continued multi-lobe lava flow activity without progress toward the coast. There was no ocean entry.

The tiltmeter on the north flank of Pu`u `O`o cone recorded false inflation produced by rainfall. At Pu`u `O`o, the lava pond in the eastern collapse pit and two sources along the south edge of the crater floor were visible. Seismic tremor levels near Pu`u `O`o remained low. GPS receivers on opposite sides of the cone recorded weak extension overall for the past few months within superimposed fluctuations that track the larger DI tilt events. The most recent (preliminary) sulfur dioxide emission rate measurement was 500 tonnes/day on June 19, 2012, from all east rift zone sources.

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 - Active lava flows within the closed-access Kahauale'a Natural Area Reserve (NAR) and the evacuated Royal Gardens subdivision can only be viewed from the air. Under favorable weather conditions, the flows can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093) and in the R2, R3, and R4 webcams. Pu`u `O`o Cone, the strip of coastal plain nearest the ocean toward which the lava is now advancing, 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