Report on Kilauea (United States) — 26 May-1 June 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
26 May-1 June 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, 26 May-1 June 2021. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
On 27 May HVO reported that Kilauea was no longer erupting; the Aviation Color Code and the Volcano Alert Level were lowered to Yellow and Advisory, respectively. A decreasing rate of lava entering the lake caused the area of the active lava lake to shrink to two small ponds by 11 May. Lava had stopped flowing into the lake sometimes during 11-13 May, and it was completely crusted over by 20 May. Weak inflation and an increase in shallow volcano tectonic earthquakes at the summit that began on 11 May also suggested that magma was staying at depth.
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.