Report on Kilauea (United States) — 14 January-20 January 2009
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
14 January-20 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, 14 January-20 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 14-20 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 on the pali. Explosions at the ocean entry were seen on 17 and 18 January. Variable winds caused the County Viewing Area to close during 14-16 January.
The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW. Variable winds occasionally caused poor air quality around the summit; on 16 January sulfur dioxide concentrations in the air reached unsafe levels. On 17 January, a geologist near the vent heard rockfalls, and rock impact and rushing sounds. Vent rim collapses the next day caused a dusting of fine tephra, and on 20 January faint incandescence from deep within the vent was noted.
Geological Summary. 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.