Report on Kilauea (United States) — 28 July-3 August 2010
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 28 July-3 August 2010
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2010. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 28 July-3 August 2010. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 28 July-3 August HVO reported that activity at Kilauea continued from the summit and the east rift zone. At the summit, the level of a lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent mainly drifted SW, dropping small amounts of ash downwind.
At the east rift zone, lava flows that broke out of the TEB lava-tube system advanced NE over coastal highway 137 towards Kalapana Gardens subdivision. Two lava lobes that had overtopped the Hakuma horst, SW of Kalapana Gardens, flowed into the ocean. The first flow initially entered the ocean on 25 July and continued to build a small delta that was about 500 m wide by 3 August. On 28 July, the second flow entered the ocean, about 545 m E of the first ocean-entry point. In addition to the activity near the ocean, scattered small active lobes of lava were seen about 1 km W of the highway 130/137 intersection.
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.