Report on Kilauea (United States) — 5 May-11 May 2021
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 5 May-11 May 2021
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2021. Report on Kilauea (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 5 May-11 May 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 W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the lava lake at a low rate during 5-11 May through a submerged inlet. The depth of the lake was 229 m by 11 May. Lava continued to circulate in the W part, though the active area continued to shrink. The E half of the lake remained solidified and comprised about 93 percent of the total area, based on thermal measurements acquired on 16 April. The sulfur dioxide emission rate was 200-300 tons per day during 5-7 May, and 150 tons per day on 10 May, continuing a downward trend that began in mid-April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
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.