Report on Kilauea (United States) — 1 February-7 February 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
1 February-7 February 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 1 February-7 February 2012. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 1-7 February, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). On 1 February lava ejections on the S edge rebuilt a low spatter cone. On 3 February two large rockfalls into the lake originated from the Halema'uma'u Crater floor. The first collapse from the N rim induced secondary collapses of the inner ledge and ejected spatter onto nearby portions of the Halema'uma'u Crater floor. The second collapse deposited large amounts of debris into the NE side of the lava lake.
At Pu'u 'O'o short lava flows issued from the SE vent during 1-2 February. Incandescence was visible on the NE and SE edges of the Pu'u 'O'o crater floor during 3-7 February and from a small cone on the NE edge during 5-7 February. The web camera showed incandescence reflected in the clouds above the pali on 2 and 4 February. During 1-7 February, thermal anomalies were seen in satellite imagery 4-5 km SE of Pu'u 'O'o cone.
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.