Report on Kilauea (United States) — 24 October-30 October 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 24 October-30 October 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 24 October-30 October 2012. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 24-30 October HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Occasional measurements indicated that the gas plume from the vent continued to deposit variable amounts of spatter, Pele's hair, and rock from the vent wall onto nearby areas. Cracking noises, audible from the Jaggar overlook and caused by rocks of the vent wall fracturing from the heat, emanated sporadically from the vent. Occasional collapses of rock from the vent walls triggered bursts of spatter that deposited a small amount of ejecta on the floor of Halema'uma'u Crater. On 25 October the lake rose to a level 27 m below Halema'uma'u Crater floor.
Lava flows accumulated at the base of the pali in the Royal Gardens subdivision and flowed across the coastal plain, but were 1.3 km from the coast. Flows also remained active on the pali. Activity at Pu'u 'O'o Crater remained elevated: the lava lake in the NE pit overflowed its rim, the vent on the N part of the crater floor produced lava flows, and lava fountaining and lava flows from the S vent were observed. Spattering was recorded from sources at the S and N edges of the crater floor.
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.