Report on Kilauea (United States) — 8 February-14 February 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 8 February-14 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, 8 February-14 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 8-14 February, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Incandescence was visible on the NE and SE edges of the Pu'u 'O'o crater floor, and strongest from a small cone on the NE edge during 8-13 February. A web camera recorded incandescence above the pali on 8 and during 12-14 February. The SE vent issued short lava flows on 14 February.
In comparison to last week, thermal anomalies increased on the flow field during 8-9 February. HVO geologists aboard an overflight on 9 February reported that the small cone on the NE edge had collapsed and was venting hot gas, and the pit was filled with a stream of lava heading NE. Geologists mapped active flows on the flow field about 6 km SE of Pu'u 'O'o and above the abandoned Royal Gardens subdivision. Web camera and satellite images indicated that the flows remained active 6 km SE of Pu'u 'O'o and above the abandoned Royal Gardens subdivision during 10-14 February, and from the Kalapana (E side of the coastal plain) on 13 February. Ground based observers reported active lava at the top of the pali on 11 and 13-14 February.
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.