Report on Kilauea (United States) — 3 March-9 March 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
3 March-9 March 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, 3 March-9 March 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 a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 2-8 March through a submerged inlet. The sulfur dioxide emission rate was 1,000 tons/day during 2-3 March, and 800 tons/day on 7 March. The depth of the western part of the lake fluctuated around 219-220 m. The E half of the lake remained solidified and lower that the W half, with the crusted E half expanding towards the W. Rangefinder measurements and visual observations indicated that the eastern and western portions of the lake were rising at the same rate, suggesting that lava was accumulating under the crusted eastern portion.
In recent weeks a part of the cone, several meters NE of the main vent, occasionally fed short (less than 100 m) lava flows that entered the lake at the crusted margins. During 5-7 March flows from this vent poured lava into the lake at several shifting inlets, though lava also accumulated on the lake margin within 50 m of the vent. By midday on 7 March the flows had built a perched lava pond on the NW lake margin, but it abruptly collapsed just after 1300. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Geological Summary. Kilauea, which overlaps the E flank of the massive Mauna Loa shield volcano, has been Hawaii's most active volcano during historical time. Eruptions are prominent in Polynesian legends; written documentation extending back to only 1820 records frequent summit and flank lava flow eruptions that were interspersed with periods of long-term lava lake activity that lasted until 1924 at Halemaumau crater, within the summit caldera. The 3 x 5 km caldera was formed in several stages about 1500 years ago and during the 18th century; eruptions have also originated from the lengthy East and SW rift zones, which extend to the sea on both sides of the volcano. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1100 years old; 70% of the volcano's surface is younger than 600 years. A long-term eruption from the East rift zone that began in 1983 has produced lava flows covering more than 100 km2, destroying nearly 200 houses and adding new coastline to the island.