Report on Kilauea (United States) — 7 January-13 January 2009
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 7 January-13 January 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, 7 January-13 January 2009. 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 7-13 January lava flowed SE through a tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex, reaching the Waikupanaha ocean entry. Surface flows were noted on the coastal plain and incandescence was seen at the base of the pali. Explosions at the ocean entry were seen on 6, 8, and 11 January. A lobe of lava called the Prince lobe, to the W of Waikupanaha, advanced to within about 160 m of the coastline.
The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Tephra production had stopped; rockfalls inside the vent continued. An infrared camera showed that the vent conduit was closed by rubble deep beneath the floor of the crater. The sulfur dioxide emission rate at the summit was 800 tonnes per day on 7 January; above the 2003-2007 average rate of 140 tonnes per day. Variable winds periodically caused sulfur dioxide concentrations in the air to reach unsafe levels and effect nearby communities, and caused the Jaggar Museum to close on 12 January.
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.