Report on Kilauea (United States) — 18 November-24 November 2009
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 18 November-24 November 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, 18 November-24 November 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 18-24 November, 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. Thermal anomalies detected by satellite and visual observations revealed active surface lava flows at locations on and at the base of the pali, at the TEB vent, and on the coastal plain. Incandescence was 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 circulating and spattering lava pond that occasionally rose above and drained back below holes in the vent cavity floor. On 21 November, a sliver of the rim collapsed and was followed by an explosion that produced a dense brown plume that dissipated after a few minutes (http://hvo.wr.usgs.gov/kilauea/update/archive/2009/Nov/HMMvent_21Nov2009_x2speed.mov). Measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 700-1,100 tonnes per day was measured during 18-20 and 23 November. The 2003-2007 average rate was 140 tonnes per day.
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.