Report on Kilauea (United States) — 12 March-18 March 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 12 March-18 March 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, 12 March-18 March 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 11-18 March at Kilauea, lava flowed into the sea at moderate levels at the West Highcastle entry. Many surface lava flows were visible along the Kohala lava flow. Tongues of lava were visible traveling down Pulama pali that were a part of the activity that began on 12 May 2002 (named the Mother's Day flow). Generally, seismicity remained at normal levels, with the long-lasting swarm of long-period earthquakes and tremor at Kilauea's summit, which began last June, continuing at moderate levels. Only small deformation changes were recorded.
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.