Report on Kilauea (United States) — 25 November-1 December 2009
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
25 November-1 December 2009
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2009. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 25 November-1 December 2009. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 25 November-1 December, HVO reported that lava flowed SE from beneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at multiple locations between Waikupanaha and an area 700 m farther to the W. A small bench collapse may have occurred on 27 November. Thermal anomalies detected by satellite and visual observations revealed active surface lava flows on the coastal plain. Incandescence was occasionally seen on the Pu'u 'O'o crater floor.
The vent in Halema'uma'u crater continued to produce a white or off-white plume that drifted mainly SW and dropped small amounts of ash downwind. Incandescence originated from a lava pond deep in the vent cavity floor; the lava pond circulated and spattered during 25-26 November and 1 December. Measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 1,000 tonnes per day were measured on 28 and 30 November. The 2003-2007 average rate was 140 tonnes per day.
According to a news article on 30 November, Hawaii county was declared a natural disaster area due to the negative impact that vog from Halema'uma'u crater has had on croplands and livestock.
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.