Report on Kilauea (United States) — 14 August-20 August 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
14 August-20 August 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Kilauea (United States). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 14 August-20 August 2002. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 14-19 August, lava flows from Kilauea sporadically entered the sea, traveling to the coast through lava tubes and also on the land surface. On the morning of the 18th several people saw part of a lava bench collapse into the sea. For most of the report period seismicity was at normal levels, with a decrease in the amount of long-period earthquakes and tremor that had been occurring since early June. On the morning of the 18th the amount of long-period seismicity increased. No significant deformation was recorded at the volcano.
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.