Report on Kilauea (United States) — 2 February-8 February 2011
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 2 February-8 February 2011
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2011. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 2 February-8 February 2011. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 2-8 February, activity continued from the summit caldera and east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within Halema'uma'u crater circulated and remained mostly stable at approximately 100 m below the crater floor, periodically rising or falling. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent that drifted mostly SW, W, and N deposited ash and fresh spatter nearby.
At the east rift zone, lava that broke out of the Quarry tube in a saddle between two rootless shields around 610 m elevation continued to advance both E and W, producing scattered surface flows. At the lowest elevation of the E branch, lava advanced along Highway 130 near Kalapana, periodically burning vegetation, and to the S towards the coast. On 4 February incandescence from the TEB vent and upper rootless shields visible on the web camera was later confirmed to be from spatter and lava flows. Lava continued to issue from each location during 5-8 February. Multiple small ocean entries were active on the W part of the Puhi-o-Kalaikini lava delta until 7 or 8 February.
In Pu'u 'O'o crater, incandescence emanated from the fuming vent in the E wall of the crater, and spatter and lava flows were produced from a cone on the N portion of the crater floor. On 7 February activity significantly increased; lava flowed from several vents including the vent on the E wall and multiple spatter cones on the N and NW areas of the floor.
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.