During 10-16 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining 50-60 m below the Overlook Crater rim. Elevated gas emissions were detected during the week of 9 September, with amounts of 3,300-6,700 tonnes per day, and persisted through this reporting period. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have fallen several kilometers away.

During 10-16 September little change was recorded from Pu`u `O`o; glow was visible overnight above several outgassing openings in the crater floor. By 16 September the NE-trending lava flow extended 15.5 km from the vent, placing the active flow front within the NW portion of the Kaohe Homesteads, a vacant forested portion of the subdivision. The flow had advanced at an average rate of 215 m/day between 12 and 15 September and continued to generate smoke and localized fires as it spread through the forest.

The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.

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)