USGS Volcano Hazards Program Volcano Update


HVO update page and observatory web site


Activity Summary: No significant changes: At the summit, the lava lake receded slightly. At Pu`u `O`o vent in the middle east rift zone, the usual sources glowed overnight and the Peace Day flow entered the ocean at several locations that produced two gas plumes spanning the Hawai`i Volcanoes National Park boundary; in addition, there was a vigorous outbreak on the pali yesterday evening. Gas emissions remained elevated.

Recent Observations at Kilauea summit: The summit tiltmeter network recorded minor fluctuations over very weak deflation. The summit lava lake level receded slightly. The most recent (preliminary) sulfur dioxide emission rate measurement was 500 tonnes/day on May 2, 2013; these measurements were made during a time of spattering (and elevated gas release). The gas plume still carries a very small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair) out of the vent and deposits it on nearby surfaces. Seismic tremor levels remained at low values.

Only one earthquakes was strong enough to be located beneath Kilauea Volcano in the past 24 hours and it plotted on south flank faults. Since mid-March, the GPS receivers located on either side of the summit caldera recorded short periods of extension and contraction across the summit area mimicking DI tilt events superposed over slow extension (slightly more than a centimeter) with no significant extension or contraction since early April; for comparison, these same GPS receivers recorded over 30 cm of extension between early 2010 and mid-February 2013.

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: There were multiple sources of glow in Pu`u `O`o Crater overnight from the usual sources - east lava pond and the north and south spatter cones. The tiltmeter on the north flank of Pu`u `O`o cone recorded very weak inflation. Seismic tremor levels near Pu`u `O`o remained low. 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.

The Peace Day lava flow continued to be active on the pali and the coastal plain with a new vigorous breakout on the pali late yesterday afternoon that reached the coastal plain from the top of the pali in about one hour. In addition, several branches of the flow have been active on the coastal plain for the last several months. 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 most robust gas plume being from the eastern entry. Multiple narrow flow branches to the west of the main flow branch were active as scattered breakouts on the pali, near the base of the pali and extending nearly to the coast.

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