During 28 July-3 August HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of a lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW, dropping small amounts of ash downwind.

At the east rift zone, lava flows that broke out of the TEB lava-tube system advanced NE over coastal highway 137 towards Kalapana Gardens subdivision. Two lava lobes that had overtopped the Hakuma horst, SW of Kalapana Gardens, flowed into the ocean. The first flow initially entered the ocean on 25 July and continued to build a small delta that was about 500 m wide by 3 August. On 28 July, the second flow entered the ocean, about 545 m E of the first ocean-entry point. In addition to the activity near the ocean, scattered small active lobes of lava were seen about 1 km W of the highway 130/137 intersection.

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)