Report on Kilauea (United States) — 6 October-12 October 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
6 October-12 October 2021
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2021. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 6 October-12 October 2021. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
HVO reported that the summit eruption at Kilauea continued in Halema`uma`u Crater during 6-12 October. At the beginning of the eruption, on 29 September, lava erupted from vents along the floor and from the W wall of the crater, though by 8 October only the W vent was active. Sulfur dioxide emissions remained high and were 5,300 tonnes per day on 8 October. A 10-m-wide, horseshoe-shaped spatter rampart had formed around the W vent and was open to the E where lava was feeding the lake. Lava fountains from the W vent were generally 12-15 m high but decreased to 4 m during 10-11 October. The total erupted volume was an estimated 15.9 million cubic meters on 8 October and the lake was as deep as 40 m on 12 October. The lava lake was not level; the W end was 2-3 m higher than the N and S parts of the lake and 5 m higher than the E end. Cooled and crusted parts of the lake’s surface overturned, or “foundered,” in all parts of the lake, though by 11 October foundering was not observed in the E. HVO noted that the central island (or raft) of cooler material from the 2020 eruption remained above the surface as the lava lake rose, and other smaller rafts had reemerged in the E and N parts of the lake. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.
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.