Report on Kilauea (United States) — 27 August-2 September 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
27 August-2 September 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, 27 August-2 September 2003. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
A M 5.0 earthquake occurred 10 km beneath Kilauea's central S flank on 26 August at 2024. It was the largest earthquake since 2 April 2000, an event that occurred in almost exactly the same spot. No significant damage was done, no cracks or rockfalls were seen, and there was no change in the eruption. During 27 August to 1 September, surface lava flows were sometimes visible on the coastal flat and upslope on Pulama pali. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger events at depths of a few kilometers. Small inflation and deflation occurred during the report week.
Geological Summary. Kilauea overlaps the E flank of the massive Mauna Loa shield volcano in the island of Hawaii. Eruptions are prominent in Polynesian legends; written documentation since 1820 records frequent summit and flank lava flow eruptions interspersed with periods of long-term lava lake activity at Halemaumau crater in the summit caldera until 1924. The 3 x 5 km caldera was formed in several stages about 1,500 years ago and during the 18th century; eruptions have also originated from the lengthy East and Southwest rift zones, which extend to the ocean in both directions. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1,100 years old; 70% of the surface is younger than 600 years. The long-term eruption from the East rift zone between 1983 and 2018 produced lava flows covering more than 100 km2, destroyed hundreds of houses, and added new coastline.
Sources: US Geological Survey Hawaiian Volcano Observatory (HVO), Associated Press