Report on Kilauea (United States) — 1 December-7 December 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
1 December-7 December 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, 1 December-7 December 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 lava effusion continued at a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 1-2 December. The rate of effusion sharply decreased, along with volcanic tremor levels, during 1600-1800 on 3 December. A small part of the vent cone collapsed at around 1700. No surface activity was observed on 5 December and most of the next day though weather conditions hindered visual confirmation; a few small hotspots around the vent were visible in thermal camera images. Lava was visible in the vent at about 1730 on 6 December and within 30 minutes was flowing into the lake. By 0300 on 7 December lava had covered the prior extent of the lava 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.