Based on overflights and web camera views when weather permitted, HVO reported that during 16-22 January activity from Kilauea's fissure segment D was concentrated at the Thanksgiving Eve Breakout (TEB) shield and satellitic shields to the SE. Lava flows from the tops and flanks of the shields traveled S and E. During 16-19 January, incandescence was observed in Pu'u 'O'o crater for less than 10 minutes at a time. During 18-19 January, the summit tiltmeter network recorded the first DI (deflation-inflation) tilt event since October 2007. A few small earthquakes were located beneath the summit, Halema'uma'u crater, and Pulama pali, and along the upper and lower E rift zones and S-flank fault.

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)