- Current Update, last updated May 2, 2014 06:32 :
Activity Summary: The eruption continued at the summit and within the east rift zone. The summit tiltmeter network recorded minor fluctuationst and the level of the circulating summit lava lake dropped slightly. At the middle east rift zone, two lava flows have been active on the Pu`u `O`o crater floor, going beyond the crater rim to the north and southeast; flows to the southeast remain active. The Kahauale`a 2 lava flow most likely continued to be active near its front but our ability to monitor it is temporarily limited. Gas emissions remained elevated.
Recent Observations at Kilauea summit: The summit tiltmeters recorded minor fluctuations and the lava-lake level dropped slightly to an estimated 33-34 m (108-112 ft) below the floor of Halema`uma`u crater. Gas emissions continued to be elevated: during the week ending on 04/29/14, the summit SO2 emission rate varied between 3,600 and 7,400 tonnes/day (see caveat below); the ambient SO2 concentrations near the vent vary greatly, are persistently great than 10 ppm, and frequently exceed 50 ppm (upper limit of detector). The gas plume typically included a small amount of ash-sized tephra (mostly fresh spatter bits and Pele's hair from the circulating lava lake); the heaviest pieces are deposited onto nearby surfaces while the finer bits can be carried several kilometers before dropping out of the plume.
Seismic tremor levels were variable with a few dropouts yesterday. Thirty-four earthquakes were strong enough to be located beneath Kilauea Volcano in the past 24 hours: 16 on south flank faults, 7 beneath the summit caldera, 2 in the Ka`oiki Pali area, 2 within the upper southwest rift zone, 7 within the upper east rift zone, and one deep quake beneath the north corner of Fern Forest Estates. GPS receivers spanning the summit caldera recorded movements mimicking the recent tilt changes and +1.5 cm of extension since mid-April; the long-term, cross-caldera measurements indicate continued extension at a rate averaging 10 cm/yr (4 in/yr) since March, 2010.
Background: The summit lava lake is within a nearly-cylindrical vent cavity with a diameter of ~160 m (520 ft) and 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 generally receding during deflation and rising during inflation.
Recent Observations at the middle east rift zone vents: During the few periods when rain wasn't obscuring the crater, POcam views show continued glow from the north and south spatter cones on the crater floor; the extent of the flow on the upper north flank of the Pu`u `O`o cone is unknown. PEcam views were clearer and showed glow from continuing overflows on the south flank and beyond the cone base presumably from the south spatter cone; On Monday, the south spatter cone flow was mapped as three branches flowing around and over the south rim of the crater.
The tiltmeter at Pu`u `O`o cone recorded about 2 microradians of tilt increase, some portion of which was caused by rain, since early yesterday morning; what is vent inflation versus rain-induced signal noise is not clear yet. The most recent sulfur-dioxide emission-rate measurement was 200 tonnes per day on April 24, 2014, from all east rift zone sources; emission rates typically ranged between 150 and 450 t/d since July 2012. GPS receivers on the north rim and south flank of Pu`u `O`o cone recorded fluctuations mimicking the tilt changes while also recording extension at a rate of about 1 cm/month.
Recent Observations of the Kahauale`a 2 flow: On Monday, April 28, HVO geologists mapped the active tip of the flow at 8.3 km (5.2 mi) northeast from Pu`u `O`o with a few patches of activity within the flow interior and at the flow edge burning forest. The most recent satellite image (April 25) was completely obstructed by clouds so, until the webcams on Pu`u `O`o are successfully re-positioned, we will have limited monitoring capability. Yesterday's overflight and re-install mission was postponed to Monday due to yesterday's torrential rain.
In general, this slow-moving lava flow has made erratic progress over the past few months. Disruption of the flow front has occurred during strong DI deflation events when the lava supply abruptly decreased causing the flow front to stagnate. DI inflation and resumption of lava supply usually follow a few days later. Breakouts reappear well behind the stalled flow front and take some time to reach the front again. In this way, the flow front has not advanced more than 1.2 km (0.75 mi) since the first time it stalled in early November, 2013.
Note: Because the recent lava flow on the Pu`u `O`o crater floor came quite close to our cameras and other monitoring equipment on the north rim of Pu`u `o`o crater last week, we are in the process of removing some of the monitoring instruments and re-positioning the PNcam and ETcam cameras out of harm's way.
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. The flows stalled and re-entered the ocean starting on November 24, 2012 until activity started to decline and the ocean entry ceased in August 20, 2013; the flow was dead by early November, 2013. 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, but a new flow (informally called Kahauale`a 2) became active in the same general area in early May. In general, activity waxes with inflation and wanes with deflation.
Hazard Summary: East rift vents and flow field - the Kahauale`a 2 flow does not pose any immediate threat to residential areas; 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. Active lava flows within forest can produce methane blasts that propel rocks and other debris into the air. All recently active lava flows are within Hawai`i Volcanoes National Park and adjacent State land managed by the Department of Land and Natural Resources or the Office of Hawaiian Affairs. 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) or the Wao Kele o Puna Forest Reserve (DLNR, OHA) and can only be viewed from the air. Under favorable weather conditions at night, distant glow from the active flows can be seen from the County Viewing Area at Kalapana (Lava hotline 961-8093) and from the end of the Chain of Craters Road within Hawai`i Volcanoes National Park. 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.
Sulfur Dioxide Emission Rate estimation caveat: Starting in 2014, we report the emission rate estimated by a new, more accurate method. The numbers increase by a factor of 2-4 but the actual emission rate has not changed. For more on this reporting change, please read http://hvo.wr.usgs.gov/volcanowatch/view.php?id=207
- Volcanic History Overview: Kilauea volcano is one of the most active and best studied volcanoes in the world and is renowned for the accessability of her eruptions. Throughout her history, Kilauea has erupted from three main areas, its summit and two rift zones. Kilauea currently has a summit caldera, but it may not always have been evident. Most eruptions are relatively gentle, sending lava flows downslope from fountains a few meters to a few hundred meters high. Over and over again these eruptions occur, gradually building up the volcano and giving it a gentle, shield-like form. Every few decades to centuries, however, powerful explosions spread ejecta across the landscape. Such explosions can be lethal, as the one in 1790 that killed scores of people in a war party near the summit of Kilauea. Such explosions can take place from either the summit or the upper rift zones. Kilauea has erupted more than 60 times in the past 150 years. The current eruption began in 1983.
- Location: Hawaii and Pacific Ocean, HI
Elevation: 1247 m
Recent Eruption: Ongoing
- Hazard Assessments: Kauahikaua. Jim, 2007, Lava Flow Hazard Assessment, as of August 2007, for Kīlauea East Rift Zone Eruptions, Hawai`i Island, Open-File Report 2007-1264.
- Link to monitoring data: Recent Earthquakes in Hawaii Page
Volcanic Alert Level: WATCH Aviation Color Code: ORANGE