DOI-USGS-HVO-2012-05-16T08:32:42-10:00 HawaiianVolcanoObservatory@vulcan4. 2012-05-16 08:32:42 Actual Update Public Geo Seismicity - Deformation - Volcanic activity - Gas emission - Thermal Anomaly Unknown Minor Unlikely 2012-05-16 08:32:42 2012-05-17 08:32:42 Hawaiian Volcano Observatory Kilauea Daily Update Activity Summary for past 24 hours: One-to-two-day-long back-to-back DI tilt events continued during which lava lake levels rose with inflation and fell with deflation; lava was generally at high levels in both summit and rift vents. At Pu`u `O`o, glow persisted from the usual sources and lava was visible in the eastern collapse pit; to the southeast, surface flows from new breakouts advanced but had not reached the ocean. Seismic tremor levels were generally low; gas emissions were elevated. Past 24 hours at Kilauea summit: The summit tiltmeter network recorded the switch to DI inflation at 7 pm last night and the lava lake level started to rise at about the same time; late last night, the spattering sink at the southwest edge of the lake became active increasing to very vigorous early this morning pushing short flows over the inner ledge. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on May 11, 2012. Although not measured this morning, small amounts of ash-sized tephra, including fresh bits of spatter from spattering at the edge of the lava lake, were likely wafted out of the vent within the gas plume and deposited on nearby surfaces. The GPS network recorded possible weak extension although the long-term trend is difficult to see through the muddle of DI events. Seismic tremor levels were low. Seven earthquakes were strong enough to be located beneath Kilauea volcano: 2 within the southwest rift zone, 3 beneath the south summit area, and 2 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 flow activity continued on the pali and the coastal plain southeast of Pu`u `O`o. Webcam images showed that the flows advanced more overnight than during the past 2 nights across the coastal plain overnight but there was no ocean entry. The tiltmeter on the north flank of Pu`u `O`o cone recorded the switch to DI inflation last night. The eastern pond lava level remained stable even during a brief lava emission from the south crater floor source between 5 and 6 pm last night. Seismic tremor levels near Pu`u `O`o remained low. GPS receivers on opposite sides of the cone recorded weak extension. The most recent (preliminary) sulfur dioxide emission rate measurement was 400 tonnes/day on May 8, 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 has continued since at Pu`u `O`o Cone, or from vents within a few kilometers to the east or west, with few interruptions. 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 on the pali and the coastal plain. 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 and Kilauea Crater - these areas are within Hawai`i Volcanoes National Park; access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm. http://hvo.wr.usgs.gov Volcano Alert Level=WATCH Aviation Color Code=ORANGE Kilauea volcano Hawaii and Pacific Ocean HI 19.421 -155.287 CAVW=1302-01-