During 23-29 January HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. on 23 January a portion of the W vent wall fell into the lake. The lake level was 35 m below the Halema'uma'u crater floor on 23 January and 38 m below the floor on 28 January.

At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a perched circulating lava lake on the NE part of the floor. Lava flows were active in a 1-km-wide area on the coastal plain. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations. On most days lava flows from multiple vents were active on the crater floor. On 25 and 26 January pilots confirmed that a lava flow remained active on the E flank of Pu'u 'O'o cone.

Geological Summary. Kilauea overlaps the E flank of the massive Mauna Loa shield volcano in the island of Hawaii. Eruptions are prominent in Polynesian legends; written documentation since 1820 records frequent summit and flank lava flow eruptions interspersed with periods of long-term lava lake activity at Halemaumau crater in the summit caldera until 1924. The 3 x 5 km caldera was formed in several stages about 1,500 years ago and during the 18th century; eruptions have also originated from the lengthy East and Southwest rift zones, which extend to the ocean in both directions. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1,100 years old; 70% of the surface is younger than 600 years. The long-term eruption from the East rift zone between 1983 and 2018 produced lava flows covering more than 100 km2, destroyed hundreds of houses, and added new coastline.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)