Report on Kilauea (United States) — 9 February-15 February 2011
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 9 February-15 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, 9 February-15 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 9-15 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 periodically changed depth. The highest level the lava rose to 72 m below the crater floor. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent drifted mostly W and deposited ash and fresh spatter nearby.
At the east rift zone, lava flows continued from one of the upper rootless shields, near the TEB vent. Two branches of the 29 November lava flow (a lava tube breach at 366 m elevation) produced scattered surface flows on the pali and coastal plain. In Pu'u 'O'o crater, incandescence emanated from a cone on the N portion of the crater floor, lava effused from a cone on the W edge of the floor, and spatter and lava flows were produced from a vent in the E crater wall. On 12 February increased activity from a cone on the N floor was characterized by lava flows and incandescent tephra ejected 40-50 m above the cone. During 14-15 February lava from a NE cone covered the E half of the crater 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.