Report on Kilauea (United States) — 10 February-16 February 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 10 February-16 February 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, 10 February-16 February 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 10-16 February. The western part of the lake deepened from 215 m to around 217 m and the lake surface actively overturned at “plate” boundaries. The W end of the lava lake was perched by 3 m above the distal margin of recent overflows. A series of surficial cracks separated the W part of the lake from the stagnant E part. Lava spillovers just N of the inlet of lava sporadically flowed around the NW margin of the perched lake. Gas jetting at two locations above the W vents and two bursts of spatter were observed during 9-10 February. The sulfur dioxide emission rate was 1,600 and 1,100 tons/day on 10 and 12 February, respectively. During 15-16 February a few lava flows were visible along the N and E margins of the E part of the lake.
Geologic Background. 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.