HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE U.S. Geological Survey Monday, January 4, 2021, 8:35 AM HST 

HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Monday, January 4, 2021, 8:35 AM HST 

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. Yesterday afternoon (Jan. 3), the lava lake was 190 m (623 ft) deep and perched about a meter (yard) above its edge. SO2 emission rates were still elevated.

Summit Observations: Sulfur dioxide emission rate measurements made Friday (Jan. 1) were about 4,400 t/d and in the range 3,000-6,500 t/d since Sunday (Dec. 27)–the same range of values that was common for emissions from the pre-2018 lava lake. Summit tiltmeters recorded weak deflationary tilt over the past three days. 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 at the onset of this eruption. There is no seismic or deformation data to indicate that additional magma is currently moving into either of Kīlauea’s rift zones.

Halemaʻumaʻu lava lake Observations: The west vents spattered from two places at the top of a small cone plastered on the northwest wall of Halemaʻumaʻu crater. Lava is also emerging as a small dome fountain in front of the west vents probably from a submerged portion of the vent. Both of these sources can be seen in the thermal webcam view of the lava lake.

The lava lake was 190 m (623 ft) deep Sunday afternoon (Jan. 3) and had a volume of 26 million cubic meters (34 million cubic yards). The most recent thermal map (Dec. 30) provided the lake dimensions as 800 by 530 m (875 by 580 yds) for a total area of 33 ha (82 acres) (https://www.usgs.gov/maps/december-30-2020-k-lauea-summit-eruption-thermal-map). The lake is now perched about a meter (yard) above its narrow edges as measured yesterday morning (Jan. 3); overflows onto the narrow edge slowly elevated a low wall around the lake similar to an above-ground swimming pool.

The main island of cooler, solidified lava floating in the lava lake continued settling in front of the west lava source filling the lake, while the other 10 or so small islands moved a bit around the east end of the lake. 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. 30 thermal map. Measurements Friday afternoon (Jan. 1) showed that the island surface was about 6 m (20 ft) above the lake surface.

Near-real time 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.