Report on Kilauea (United States) — 3 December-9 December 2008
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
3 December-9 December 2008
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2008. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 3 December-9 December 2008. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
HVO reported that during 3-9 December lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Incandescence was occasionally seen at the TEB vent, and surface flows were noted on and at the base of the pali. On 6 December, a few explosions originated from the ocean entry. Observers reported that a small bench collapse that occurred sometime between 6 and 7 December sent boulders up to 0.5 m in diameter inland about 50-75 m.
Earthquakes were variously located beneath and to the S of the caldera, along the SW rift zone, and along the S-flank fault. The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW and deposited small amounts of tephra. Night-time incandescence was rarely seen at the base of the plume, and sounds resembling rockfalls were heard in the vicinity of the crater. During 2-4 December, the plume drifted NW and high concentrations of sulfur dioxide were measured at various locations. On 4 December, hybrid earthquakes were followed by several minutes of dense brown emissions. A vent rim collapse was seen on 5 December after rockfall and booming sounds were heard, and brown ash was emitted. The sulfur dioxide emission rate at the summit was 1,000 and 500 tonnes per day on 4 and 5 December, respectively; the 2003-2007 average rate was 140 tonnes per day.
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.