Report on Kilauea (United States) — 17 November-23 November 2004
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 17 November-23 November 2004
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2004. Report on Kilauea (United States). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 17 November-23 November 2004. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
Lava from Kilauea's PKK flow continued to enter the sea at the newly formed lava delta at eastern Lae`apuki delta during 17-23 November. Fieldwork on 18 November determined that the new lava delta is 260 m long and extends about 80 m beyond pre-existing land (the front of the old Lae`apuki delta). The area of the delta is about 1.2 ha. One entry point was on the far west end of the delta, but most of the activity was east of center. During 17-23 November, all vents in the crater of Pu`u `O`o were incandescent. Seismicity at Kilauea's summit increased during the report period, with numerous small long-period earthquakes coming from the southern and southeastern parts of the caldera. Tremor remained low to absent, however. The tremor at Pu`u `O`o remained at moderate strength. No significant deformation occurred.
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.