USGS Volcano Hazards Program Volcano Update
HVO update page and observatory web site
Activity Summary for past 24 hours: At the summit, rockfalls and rise/fall events dominate lava lake activity while strong DI deflation continued. At Pu`u `O`o, there were no significant changes in the crater or on its flanks. To the southeast of Pu`u `O`o, scattered lava flows were active on the coastal plain near the base of the pali. Seismic tremor levels were slightly elevated at the summit and low elsewhere. Gas emissions were elevated.
Past 24 hours at Kilauea summit: The low lava lake level left the cavity walls unsupported and there have been several collapses of wall rock and parts of the inner ledge. Last night, there were two major collapses - the first at 11 pm took out a large chunk of the westernmost inner ledge and the second, 25 minutes later, removed a wide swath of the northeastern cavity wall above the ledge. Both rockfalls significantly disrupted the lake's circulation which resumed a more normal pattern, from northwest to southeast, by 1:30 am this morning.
The summit tiltmeters recorded continued DI deflation with two noticeable inflationary offsets in response to the large rockfalls. The lava lake level was generally quite low and the near-midnight rockfalls occurred just after a long rise/fall event that started about 3:45 pm yesterday; another rise/fall event started just after the first and largest rockfall that continued through this morning. The most recent (preliminary) sulfur dioxide emission rate measurement was 700 tonnes/day on August 27, 2012; this value was a typical background level between rise/fall events. Small amounts of ash-sized tephra (spatter bits and Pele's hair) were carried out of the vent in the gas plume and deposited on nearby surfaces.
Seismic tremor levels remained slightly elevated but varied with the changing activity of spattering lava sinks and rise/fall events within the lava lake. Nine earthquakes were strong enough to be located beneath Kilauea volcano: 4 within the southwest rift zone, 1 beneath Halema`uma`u Crater, 3 within the upper east rift zone, and 1 north of the middle east rift zone.
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: The overall vigor of flows southeast of Pu`u `O`o remained weak when viewed through Webcams, with scattered flow activity on the coastal plain more than 2 km (1.2 mi) from the coast; if weather permits, we will move one of our webcams from the pali down to the coastal plain so that it will provide views of lava flows on the pali. The Kalapana Viewing Area crew have been occasionally reporting views of lava flows high on the pali consistent with the trend of activity moving slowly upslope over the past several months. There was no ocean entry.
Incandescence at Pu`u `O`o continued to be dominated by the two small pits on the crater floor. The long-lived northeastern one holds a small lava lake; the southern one must also hold a lava lake based on circumstantial evidence and we hope to get visual confirmation from HVO geologists on today's overflight. The glowing spot at the base of the southeast flank of Pu`u `O`o, marking a collapse in the roof of the lava tube, was also bright.
The tiltmeter on the north flank of Pu`u `O`o cone recorded slowing deflation that flattened overnight - possibly the effect of rain. Seismic tremor levels near Pu`u `O`o remained low. The most recent (preliminary) sulfur dioxide emission rate measurement was 400 tonnes/day on August 27, 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 within 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.
Past 24 hours at Kilauea summit: The low lava lake level left the cavity walls unsupported and there have been several collapses of wall rock and parts of the inner ledge. Last night, there were two major collapses - the first at 11 pm took out a large chunk of the westernmost inner ledge and the second, 25 minutes later, removed a wide swath of the northeastern cavity wall above the ledge. Both rockfalls significantly disrupted the lake's circulation which resumed a more normal pattern, from northwest to southeast, by 1:30 am this morning.
The summit tiltmeters recorded continued DI deflation with two noticeable inflationary offsets in response to the large rockfalls. The lava lake level was generally quite low and the near-midnight rockfalls occurred just after a long rise/fall event that started about 3:45 pm yesterday; another rise/fall event started just after the first and largest rockfall that continued through this morning. The most recent (preliminary) sulfur dioxide emission rate measurement was 700 tonnes/day on August 27, 2012; this value was a typical background level between rise/fall events. Small amounts of ash-sized tephra (spatter bits and Pele's hair) were carried out of the vent in the gas plume and deposited on nearby surfaces.
Seismic tremor levels remained slightly elevated but varied with the changing activity of spattering lava sinks and rise/fall events within the lava lake. Nine earthquakes were strong enough to be located beneath Kilauea volcano: 4 within the southwest rift zone, 1 beneath Halema`uma`u Crater, 3 within the upper east rift zone, and 1 north of the middle east rift zone.
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: The overall vigor of flows southeast of Pu`u `O`o remained weak when viewed through Webcams, with scattered flow activity on the coastal plain more than 2 km (1.2 mi) from the coast; if weather permits, we will move one of our webcams from the pali down to the coastal plain so that it will provide views of lava flows on the pali. The Kalapana Viewing Area crew have been occasionally reporting views of lava flows high on the pali consistent with the trend of activity moving slowly upslope over the past several months. There was no ocean entry.
Incandescence at Pu`u `O`o continued to be dominated by the two small pits on the crater floor. The long-lived northeastern one holds a small lava lake; the southern one must also hold a lava lake based on circumstantial evidence and we hope to get visual confirmation from HVO geologists on today's overflight. The glowing spot at the base of the southeast flank of Pu`u `O`o, marking a collapse in the roof of the lava tube, was also bright.
The tiltmeter on the north flank of Pu`u `O`o cone recorded slowing deflation that flattened overnight - possibly the effect of rain. Seismic tremor levels near Pu`u `O`o remained low. The most recent (preliminary) sulfur dioxide emission rate measurement was 400 tonnes/day on August 27, 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 within 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
