Hawaiian Volcano Observatory’s Kilauea summit eruption update, as of Wed., Dec. 30, at 8 a.m.:

KILAUEA VOLCANO (VNUM #332010)
19°25’16” N 155°17’13” W, Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Activity Summary: Lava activity is confined to Halemaʻumaʻu with lava erupting from vents on the northwest side of the crater. As of 3:45 am this morning (Dec. 30), the lava lake was 181 m (593 ft) deep with a narrow black ledge around it. Reduced, but still elevated, SO2 emissions were measured Monday (Dec. 28).

Summit Observations: Preliminary analysis of sulfur dioxide emission rates measured Monday (Dec. 28) show that the rates are about 3,300 tonnes/day– slightly lower than the Dec. 27 rate of 5,500 t/d, but still elevated; both values were in the range of emission rates common for the pre-2018 lava lake. Summit tiltmeters continued to record weak inflationary tilt starting on Monday (Dec. 26). Seismicity remained elevated but stable, with steady elevated tremor and a few minor earthquakes.

East Rift Zone Observations: Geodetic monitors indicate that the upper portion of the East Rift Zone (between the summit and Puʻu ʻŌʻō) contracted while the summit deflated. There is no seismic or deformation data to indicate that magma is moving into either of Kīlauea’s rift zones.

Halemaʻumaʻu lava lake Observations: The west vents spattered while erupting lava flowed through crusted-over channels into a lava lake within Halemaʻumaʻu crater.

The lava lake within Halemaʻumaʻu crater has changed little in the past few days and was about 181 m (593 ft) deep as of early this morning (Dec. 30). The lake volume was about 23 million cubic meters (30 million cubic yards or 5.2 billion gallons). The most recent thermal map (Dec. 28) provided the lake dimensions as 770 by 490 m (840 by 535 yds) for a total area of 29 ha (72 acres). The narrow (10-30 m or 11-22 yd) ledge around the lake was about 1-2 m (1-2 yds) above the active lake surface (https://www.usgs.gov/maps/december-28-2020-k-lauea-summit-eruption-thermal-map).

Over the past day, the main island of cooler, solidified lava floating in the lava lake drifted slightly to the west in the lake and rotated counter-clockwise. The 10 or so much smaller islands to the east remained stationary. The main island measured about 250 m (820 ft) in length, 135 m (440 ft) in width, and about 3 ha (7 acres) in area based on the Dec. 28 thermal map. Measurements on Dec. 27 show that the island surface was about 6 m (20 ft) above the lake surface.

Webcam views of the lava lake can be found here: https://volcanoes.usgs.gov/volcanoes/kilauea/multimedia_webcams.html.

Hazard Analysis: High levels of volcanic gas, rockfalls, explosions, and volcanic glass particles are the primary hazards of concern regarding this new activity at Kīlauea’s summit. Large amounts of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are continuously released during eruptions of Kīlauea Volcano. As SO2 is released from the summit during this new eruption, it will react in the atmosphere with oxygen, sunlight, moisture, and other gases and particles, and within hours to days, convert to fine particles. The particles scatter sunlight and cause the visible haze that has been observed downwind of Kīlauea, known as vog (volcanic smog), during previous summit eruptions. Vog creates the potential for airborne health hazards to residents and visitors, damages agricultural crops and other plants, and affects livestock operations. Rockfalls and minor explosions, such as the ones that occurred during the 2008–2018 lava lake eruption at Kīlauea summit, may occur suddenly and without warning. This underscores the extremely hazardous nature of Kīlauea caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since late 2007. Pele’s hair and other lightweight volcanic glass fragments from the lava fountains within Halemaʻumaʻu will fall downwind of the fissure vents and lava lake, dusting the ground within a few hundred meters (yards) of the vent. High winds may waft lighter particles to greater distances. Residents are urged to minimize exposure to these volcanic particles, which can cause skin and eye irritation similar to volcanic ash.

Vog information can be found at https://vog.ivhhn.org/.

Photo:  HVO field crews observed activity within Halema‘uma‘u, at Kīlauea Volcano’s summit, overnight from within a closed area of Hawai‘i Volcanoes National Park. The area remains closed to the public for safety reasons and HVO field crews are equipped with a range of specialized safety gear and personal protective equipment. In the early hours of December 30, the western vent in the wall of Halema‘uma‘u continued to erupt primarily effusively (flowing lava), but sporadic strombolian activity (minor explosions ejecting lava into the air) was also observed at the top of the west vent. USGS photo by H. Dietterich.