USGS Volcano Hazards Program Volcano Update


HVO update page and observatory web site


Activity Summary: At the summit, tiltmeters recorded the switch to DI inflationary tilt and the lava lake level started to rise. At Pu`u `O`o vent in the middle east rift zone, there was no new activity within the crater but lava flows remained active on the north base of the cone. The Peace Day pali flow remained active on the coastal plain while the main flow branch continued to enter the ocean in at least 2 locations spanning the Hawai`i Volcanoes National Park boundary. Gas emissions remained elevated.

Recent Observations at Kilauea summit: After recording a little more than 3 microradians of DI deflationary tilt, the summit tiltmeter network recorded the switch to DI inflationary tilt just before 3 am this morning. the summit lava lake continued to drop slowly, leveled through the early morning, and started to rise around 5 am this morning. The most recent sulfur dioxide emission rate measurement was 700 t/d on May 14, 2013; these measurements are minimums because the data are acquired close to the vent where the plume is dense. The plume also contained a very small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair) that was deposited on nearby surfaces. Seismic tremor levels remained at low values with a single 90-minute drop in value starting around 4 am after inflation started.

Six earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 1 northeast of the summit caldera, 2 within the east rift zone, and 3 on south flank faults clustered near the eastern boundary of the flow field. The GPS receivers located on either side of the summit caldera recorded slowing contraction that started on May 11 when summit inflation slowed and 2 days before DI deflation began.

Background: The summit lava lake is within an ~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 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 receding during deflation and rising during inflation.

Recent Observations at the middle east rift zone vents: Only glow was seen from the east pond and spatter cones on the crater floor. The tiltmeter on the north flank of Pu`u `O`o cone continued recording DI deflationary tilt with more minor fluctuations. GPS receivers on the north and south flanks of Pu`u `O`o cone recorded slowing contraction since May 11 mimicking Pu`u `O`o flank tilt. The most recent (preliminary) sulfur dioxide emission rate measurement was 300 tonnes/day on April 26, 2013, from all east rift zone sources; these values have ranged between 150 and 450 t/d in 2013.

There were two sets of lava flows outside Pu`u `O`o cone: lava continued to spread out and advance to the north from the base of Pu`u `O`o cone. The Peace Day pali breakout continued with scattered activity across the coastal plain while the main branch of the Peace Day flow continued to enter the ocean at 2 persistent locations (inside and outside Hawai`i Volcanoes National Park). The western ocean entry plume has been weak to nonexistent over the past few days.

HAZARD ALERT: Lava entering the ocean builds lava deltas. The lava delta and adjacent areas are some of the most hazardous areas on the flow field. Frequent delta/bench collapses give little warning, can produce explosions capable of throwing both dense and molten rocks hundreds of meters (yards) in all directions (inland as well as out to sea), and can produce damaging local waves. The steam plume produced by lava entering the ocean contains fine lava fragments and an assortment of acid droplets that can be harmful to your health. The rapidly changing conditions near the ocean entry have been responsible for many injuries and a few deaths.

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. Since late December 2011, the flows have remained intermittently active on the pali and the coastal plain and finally re-entered the ocean starting on November 24, 2012. 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. 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; the lava flows do not pose a hazard to any structures not already within the County-declared mandatory evacuation zone. Lava deltas, which can collapse into the ocean without warning, are extremely hazardous and should be avoided (see HAZARD ALERT above). 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) and the abandoned Royal Gardens subdivision and can only be viewed from the air. A small part of the western flow field near the coast in within Hawai`i Volcanoes National Park (see below for access info). Under favorable weather conditions, active flows-when present-can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093). 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 http://www.nps.gov/havo/planyourvisit/lava2.htm.

Update in Common Alerting Protocol (CAP) format