Logo link to homepage

Report on Kilauea (United States) — 14 December-20 December 2011

Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 December-20 December 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, 14 December-20 December 2011. Smithsonian Institution and US Geological Survey.

Volcano Profile |  Weekly Report (14 December-20 December 2011)


Kilauea

United States

19.421°N, 155.287°W; summit elev. 1222 m

All times are local (unless otherwise noted)


During 14-20 December, 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). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby.

Incandescence was visible along the 21 September fissure on the SE flank of Pu'u 'O'o cone, from a skylight on the lava tube, and from small spatter cones on the E and S edges of the Pu'u 'O'o crater floor. Pahoehoe flows that were 300-400 m wide, fed by lava tubes from the fissure, continued to be active about 6.8 km SE of Pu'u 'O'o and entered the ocean W of Ka'ili'ili. The lava delta now extends 15-20 m into the ocean at a point 6.4 km W of the Chain of Craters Road. During 17-20 December the lava flow branched, with lobes advancing NE and W into the ocean. Infrequent plumes were observed from the ocean entry during 18-20 December.

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.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)