USGS Volcano Hazards Program Volcano Update


HVO update page and observatory web site


Activity Summary: There were no significant changes. Kilauea continued to erupt at its summit, where the lava lake was circulating and stable, and in the middle east rift zone, where the Pu`u `O`o vent fed two lava flows: the Kahauale`a lava flow, which extends more than 4 km to the northeast and continued to be active over older Pu`u `O`o flows, and the Peace Day flow, which extends more than 10 km to the southeast and was entering the ocean in two main locations spanning the National Park boundary. Gas emissions remained elevated.

Recent Observations at Kilauea summit: The summit tiltmeter network recorded very little change and the lava lake continued to circulate and its level changed very little. The most recent (preliminary) sulfur dioxide emission rate measurement was 600 tonnes/day on March 29, 2013; this value is an average of emissions during a period where the spattering started during the measurement; IOW, the last measurements were higher than the first and spattering resumed midway during the measurement set. A very small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair) was carried out of the vent in the gas plume and deposited on nearby surfaces.

Seismic tremor levels were low - tremor values and SO2 concentrations near the vent sporadically dropped to near-zero values when spattering was largely absent. Seven earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 4 west of the summit in the Ka`oiki Pali area, 1 south of the summit and 3 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 contraction; for comparison, these same GPS receivers recorded over 30 cm of extension between early 2010 and mid-February 2013 and no long-term change until mid-March.

Background: The summit lava lake is deep 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. 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: Within the Pu`u `O`o crater, the usual four spatter cones on the crater floor continued to glow overnight. The tiltmeter on the north flank of Pu`u `O`o cone recorded minor fluctuations. Seismic tremor levels near Pu`u `O`o remained low. The most recent (preliminary) sulfur dioxide emission rate measurement was 500 tonnes/day on March 29, 2013, from all east rift zone sources; these values have typically been between 200 and 300 t/d from November through January and 200-400 t/d through February. Two lava flows (Peace Day and Kahauale`a) were fed by lava tubes extending from Pu`u `O`o:

Peace Day lava flow activity on the pali and the coastal plain continued in several areas with no significant changes - a patch of active breakouts just above the pali about 5 km (3 mi) southeast from Pu`u `O`o (visible in occasional satellite images and from the Kalapana Viewing Area but not in our Webcams), and several branches on the coastal plain. The main branch of the Peace Day flow continued to enter the ocean at two persistent locations (inside and outside Hawai`i Volcanoes National Park). Two narrow flow branches to the west were active as scattered breakouts extending close to the coast within Hawai`i Volcanoes National Park.

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.

The Kahauale`a flow remained active along the north base of the 2007 perched channel over older flows from the 30-year ongoing eruption with scattered activity to the northeast from Pu`u `O`o more than 4.4 km (2.7 mi) across the Kahauale`a NAR and into Wao Kele o Puna Forest Reserve. Over the past several days, the only active part of the flow visible in the PNcam suggests that it continued to be active on older Pu`u `O`o flows. The active areas appeared to be either weakening or advancing farther away from the PNcam.

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 started from the spatter cone/lava lake at the northeast edge of the Pu`u `o`o crater floor in mid-January, 2013, and advanced north to the base of the cone before turning to the northeast and splitting at the base of the 2007 perched channel. 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