HAWAII VOLCANOES NATIONAL PARK, Hawaii: Volcano scientists reported continued activity on the coastal plain and a lava pond in Pu’u ‘Ō’ō this weekend.

This video was released by the USGS Hawaiian Volcano Observatory on Friday. A small lava pond, set within a collapse pit, has been active in the eastern portion of Pu’u ‘Ō’o crater for the past several weeks. At the east margin of the lava pond, lava sinks back into the system, with frequent spatter bursts sourced from this downwelling spot.

Flows were spread across a broad expanse on the coastal plain, and continue to slowly advance towards the ocean, but have made only minor progress over the past week. This image combines a thermal image with a normal photograph, with the bright yellow areas showing active breakouts and red/purple areas showing warm, but inactive, flow areas. The numerous fume sources on the pali mark the path of the lava tube in Royal Gardens subdivision. Compare this image to a similar one acquired on April 5.

In this photo, an HVO geologist is seen using a rock hammer to take a sample of an active pāhoehoe toe.Regular geochemical analyses of these samples provides insight on the changing magmatic plumbing system.

The latest from the Kilauea Update section on the USGS HVO website:

Activity Summary for past 24 hours: The summit continued to inflate slowly while back-to-back DI events and sympathetic summit lava lake level fluctuations continued. Glow from the summit lava lake was visible within the Halema`uma`u gas plume and was episodically quite bright during the most recent high lava stand early this morning. At Pu`u `O`o, glow persisted from the usual sources within Pu`u `O`o crater. To the southeast, surface flows continued to spread on the coastal plain but there was no ocean entry. Seismic tremor levels were low; gas emissions were elevated.

Past 24 hours at Kilauea summit: Two dramatic high lava stands occurred between 2 and 7 pm yesterday with the lava lake levels rising above and swamping most of the inner ledge before receding each time. DI deflation started at 7:10 pm last night but the lava lake surface did not drop; instead, it stayed stable and abruptly rose a third time for a high lava stand between 2 and 4 am this morning before returning to the same stable level. The most recent (preliminary) sulfur dioxide emission rate measurement was 400 tonnes/day on March 29, 2012.

Since mid-October 2011, the summit GPS network recorded ~1 cm/mo extension indicating continuing long-term summit inflation. Seismic tremor levels remained low. Six earthquakes were strong enough to be located beneath Kilauea volcano: 2 within the lower southwest rift zone, 1 deep quake within the Ka`oiki Pali area to the west of the summit, and 3 scattered on south flank faults.

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 70 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 (70 m or 230 ft below the floor of Halema`uma`u Crater in April, 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: Lava flows continued to be active on the pali and the coastal plain southeast of Pu`u `O`o. The webcams document continued activity that served to broaden the flow rather than produce progress toward the coast (see images). Flows are still about 1.4 km (0.9 mi) from the ocean.

The tiltmeter on the north flank of Pu`u `O`o cone recorded weak DI deflation starting at 11 pm last night (about 4 hours after the summit). Strong glow was persistent from the usual sources: a small lava pond within the collapse pit on the east edge (see new movie), the small spatter cone on the southeast edge of the floor (the source of several brief lava flows recently), and the uppermost lava tube system on the east flank of Pu`u `O`o cone. Seismic tremor levels near Pu`u `O`o were low. GPS receivers on opposite sides of the cone recorded intermittent, but minor, extension over the past few months. The most recent (preliminary) sulfur dioxide emission rate measurement was 450 tonnes/day on March 29, 2012, from all east rift zone sources; the winds have been too weak to make accurate measurements.

Background: The eruption in Kilauea’s middle east rift zone started with a fissure eruption on January 3, 1983, and has continued since at Pu`u `O`o Cone, or from vents within a few kilometers to the east or west, with few interruptions. 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. The ocean entry has been inactive since late December but the flows have remained intermittently active above or on the pali. 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 – There are active lava flows within the closed-access Kahauale’a Natural Area Reserve (NAR) and the evacuated Royal Gardens subdivision, which 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 and Kilauea Crater – these areas are within Hawai`i Volcanoes National Park; access and viewing information can be found at http://www.nps.gov/havo/planyourvisit/lava2.htm.