Report on Kilauea (United States) — 5 September-11 September 2007
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 5 September-11 September 2007
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2007. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 5 September-11 September 2007. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
HVO reported that during 5-11 September fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing 'a'a lava flow that frequently overflowed its channel edges. Several of the lava flows that branched from the main channel continued to advance. A section of the lava flow's channel collapsed during 6-7 September, and several new lava flows branched away and advanced less than 1 km. On 8 September, the level of the lava in the channel was about 3-8 m below the previous level before the channel was breached. On 9 September, the channel was again full and overflowing. On 11 September, a breakout occurred at the fissure vent of segment D, sending a small lava flow to the S. A few small earthquakes were located beneath Halema'uma'u crater, the S flank, and the SW rift zone during the reporting 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.