Report on Kilauea (United States) — 29 August-4 September 2012
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 29 August-4 September 2012
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2012. Report on Kilauea (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 29 August-4 September 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 28 August-4 September HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The gas plume from the vent continued to deposit variable amounts of spatter and Pele's hair onto nearby areas. On 28 August two major collapses of the inner wall significantly disrupted the lake's circulation.
Lava flows were periodically active on the pali and the coastal plain. At Pu'u 'O'o, a collapse of the crater floor just before 0400 on 30 August enlarged the newer pit crater at the S edge, making it appear slightly larger in the webcam views than the older, active, pit crater on the E edge. A new pit crater formed at the N edge of the floor after 1000, and by 1300 it was filled with lava. The N rim of the E pit crater fell into the lava lake there just before 1700. During 30-31 August incandescence emanated from the lava lake in the E pit crater but was absent from the S pit crater. A few scattered areas of flow activity on the coastal plain more than 2 km from the coast were visible on web cameras. On 1 September glow emanated from the E and S pit craters. Crusted lava filled the N pit crater and sagged, and a couple of small lava flows traveled from the edge onto the sagging crust. The N pit appeared to be a passive lava lake, without a direct source of magma underneath. A collapse in the roof of the lava tube at the base of the SE flank of Pu'u 'O'o continued to glow but was less bright the next day.
Geological Summary. Kilauea overlaps the E flank of the massive Mauna Loa shield volcano in the island of Hawaii. Eruptions are prominent in Polynesian legends; written documentation since 1820 records frequent summit and flank lava flow eruptions interspersed with periods of long-term lava lake activity at Halemaumau crater in the summit caldera until 1924. The 3 x 5 km caldera was formed in several stages about 1,500 years ago and during the 18th century; eruptions have also originated from the lengthy East and Southwest rift zones, which extend to the ocean in both directions. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1,100 years old; 70% of the surface is younger than 600 years. The long-term eruption from the East rift zone between 1983 and 2018 produced lava flows covering more than 100 km2, destroyed hundreds of houses, and added new coastline.