USGS-HVO Update on Kīlauea, January 3rd

Activity Summary: Lava activity is confined to Halemaʻumaʻu with lava erupting from vents on the northwest side of the crater. Yesterday afternoon (Jan. 2), 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 the pre-2018 lava lake. Summit tiltmeters recorded weak deflationary tilt over the past two 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. 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 from two places at the top of a small cone plastered on the northwest wall of Halemaʻumaʻu crater. Lava is also emerging in a small dome fountain above the lake crust 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 yesterday afternoon (Jan. 2). 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 east and west edges and discontinuously on its north edge as measured this morning (Jan. 3). Over the past day, the main island of cooler, solidified lava floating in the lava lake continued settling in front of the west lava source filling the lake around midnight, while the other 10 or so small islands remained relatively stationary 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. Vog information can be found at https://vog.ivhhn.org/. Please see this Hawaii Volcanoes National Park Press Release “How to Safely View the New Eruption in Hawaiʻi Volcanoes National Park” at https://www.nps.gov/havo/learn/news/20201221_nr_new-summit-eruption-kilauea.htm. The Hawaiian Volcano Observatory (HVO) continues to closely monitor Kīlauea’s seismicity, deformation, and gas emissions for any sign of reactivation, and maintains visual surveillance of the summit and the East Rift Zone. HVO will continue to issue daily updates and additional messages as needed. 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 Images and captions from USGS: - Image 1: West vents spattering. Lava lake ~623 ft deep, ~82 acres. SO2 ranges from 3,000-6,500 t/d, similar to pre-2018 lava lake. Weak deflationary tilt. Seismicity elevated but stable - some tremor & minor EQs. - Image 2: Early this morning, the west vents in Halema‘uma‘u spattered from two places at the top of a small cone plastered on the northwest wall. This process can be seen in Kīlauea Volcano's summit F1 thermal webcam view of the lava lake. USGS photo by H. Dietterich. - Image 3: At Halema‘uma‘u, the west vents (visible in the foreground of this photo as two glowing holes on a cone-shaped feature) erupt occasional spatter. Lava is also emerging in a small dome fountain above the lake crust in front of the west vents, probably from a submerged portion of the vent (visible in the background of this photo as a bright spot with lava crust boundaries emanating from it like a spider web). These processes can be observed in Kīlauea Volcano's summit F1 thermal webcam view of the lava lake. USGS photo by H. Dietterich. - Image 4: Graph showing the depth of the Halema‘uma‘u crater lava lake at Kīlauea Volcano's summit. HVO scientists measure the Kīlauea summit lava level using a small laser rangefinder mounted on a tripod. Measurements began one day after the start of the eruption on December 20, 2020 and are updated by geologists making observations from the field. HVO field crews use a laser range finder to measure the vertical distance between points of known elevation and the lava lake surface. Multiple measurements are taken and the average solution is plotted. Variations in plotted depth can occur due to alternating field crews, the uneven surface of the lava lake, or laser rangefinder returns on gas rather than the lake surface.