Report on Kilauea (United States) — 17 December-23 December 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 17 December-23 December 2003
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2003. Report on Kilauea (United States). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 17 December-23 December 2003. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 18-22 December, eruptive activity at the Pu`u `O`o vent of Kilauea continued unabated. Fresh lava from the southwestern vents within Pu`u `O`o coated a quarter of the crater floor. No active flows were observed on Pulama pali or the coastal flat below Paliuli and no lava entered the ocean. As of 18 December surface lava flows at high elevations along the Mother's Day lava-tube system ignited trees. A few small earthquakes were recorded at Kilauea's summit along with steady weak tremor. Volcanic tremor continuously occurred at moderate levels at Pu`u `O`o and small amounts of inflation and deflation were detected during the report period.
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.