During 7-13 September HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. The lake level fluctuated between 5 and 20 m below the Halema’uma’u floor, and was easily visible from the Jaggar Museum (NW rim of Kilauea Caldera). The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at multiple areas near Kamokuna. A large section of the W part of the delta had collapsed on 5 September, causing a small explosion. Scattered breakouts were active 1.7-2 km inland from the coast.

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)