USGS-HVO Update on Kīlauea, January 6th 2021

Tracker Summary: Western Fissure still active with low fountaining and weak spatter. The lava lake is slowly gaining depth, and now at ~630 feet deep. The top layer of the lava lake is perched above the edges, creating a perched pond roughly 1-2 meters elevated from the perimeter. ---------------------------- Full update from USGS: Activity Summary: Lava activity is confined to Halemaʻumaʻu with lava erupting from vents on the northwest side of the crater. Tuesday afternoon (Jan. 5), the lava lake was 192 m (630 ft) deep and perched 1-2 m (1-2 yds) above its edge. SO2 emission rates were still elevated. Summit Observations: Sulfur dioxide emission rate measurements made on Sunday (Jan. 3) were in the range 3,000-6,500 t/d since last 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 since Jan. 1. 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 the top of a small cone plastered on the northwest wall of Halemaʻumaʻu crater. This morning, lava is flowing down a narrow channel to the lake and feeding a small dome fountain in front of the west vents probably from a submerged portion of the vent. The lava lake was 192 m (630 ft) deep Tuesday afternoon (Jan. 5) and had a volume of about 27 million cubic meters (35 million cubic yards). The most recent thermal map (Jan. 5) provided the perched lake dimensions as 760 by 520 m (830 by 570 yds) for a total area of 28 ha (70 acres)--slightly smaller than on Dec. 30 when the pervious thermal map was made. As of Tuesday (Jan. 5), the lake was perched about 1-2 m (1-2 yds) above its narrow edges; overflows onto the narrow edge slowly elevated a low wall around the lake similar to the wall around an above-ground swimming pool. The main island of cooler, solidified lava floating in the lava lake continued rotating counter-clockwise, in front of the west lava source filling the lake, while the 11 smaller islands moved a bit but remained in the east end of the lake. The dimensions of the main island remained the same: about 250 m (820 ft) in length, 135 m (440 ft) in width, and about 3 ha (7 acres) in area based on the Jan. 5 thermal map. Measurements Friday afternoon (Jan. 1) showed that the island surface was about 6 m (20 ft) above the lake surface. Yesterday afternoon, (Jan. 4), the island was measured as 7-8 m (8-9 yds) higher above the lake surface. ---- Images and captions from USGS (in order that they appear) - Image 1: The ongoing eruption at Kīlauea Volcano’s summit, within Halema‘uma‘u crater, continues to erupt from the west vent (left). Yesterday evening, January 4, the lava lake was measured at approximately 191 m (626 ft) deep. No major changes have been observed over the past week. HVO scientists continue to monitor the eruption within an area of Hawai‘i Volcanoes National Park that remains closed to the public for safety reasons. View is looking to the north. USGS photo taken by M. Patrick on January 4 at 6:08 p.m. HST. - Image 2: At approximately 8:00 a.m. HST this morning there was a small breakout from the lower part of the west vent tube. This telephoto aerial photograph taken at about 8:30 a.m. HST during a HVO overflight of Halema‘uma‘u crater, shows the newly exposed lava channel entering the lava lake. Lava also continues to enter the lava lake through the tube, which is producing the small dome fountain at the lake margin below (lower center). USGS photo taken by B. Carr on January 5, 2021. - Image/map 3: Topography of Halema'uma'u crater, at the summit of Kīlauea Volcano, on December 26, 2020 (left), and January 5, 2021 (right). These Digital Elevation Models (DEMs) are created from aerial imagery collected during helicopter overflights. They show that the lava lake within Halema'uma'u continues to rise and deepen. Eruptive vents are evident on the wall of Halema'uma'u, with the north, inactive vent being progressively buried as the lava lake rises. The largest "island" that was oriented in an east-west direction along its long axis on Dec. 26 was oriented in a north-south direction on Jan. 5, and had drifted closer to west end of the lava lake and active west vents. As of yesterday, Jan. 5, the lava lake is 192 m (630 ft) deep. Halema'uma'u DEMs by B. Carr. Graphic by K. Mulliken. -Image 4: The eruption from the west vent in Halema‘uma‘u crater continues at Kīlauea’s summit. Nighttime telephoto images from January 2 (left) and January 4 (right) compare the recent changes in the dome fountain at the west vent inlet into the lava lake. By January 4, the small dome fountain is more uniform and less elongated. USGS photos by M. Patrick.