Report on Kilauea (United States) — 15 August-21 August 2007
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 15 August-21 August 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, 15 August-21 August 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 fissure segment D from Kilauea's 21 July fissure eruption continued to feed an advancing 'a'a lava flow during 15-21 August. Aerial observations on 17 August revealed that the first 'a'a flow had advanced 24 m since 13 August but was inactive. The second 'a'a channel had advanced 2.3 km along the N side of the first flow. Smoke from burning vegetation was visible near the flow front. On 18 August, a new and widening crack was seen on the rim of Pu'u 'O'o crater. A few small earthquakes were located beneath the summit, Halema'uma'u crater, and the S flank.
On 14 August, approximately 17.8 hectares (44 acres) of the East Lae'apuki bench collapsed, possibly due to a M 5.4 earthquake, high surf from hurricane Flossie, or a combination of both.
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.