Report on Kilauea (United States) — 1 April-7 April 2015
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 1 April-7 April 2015
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2015. Report on Kilauea (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 1 April-7 April 2015. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 1-7 April HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active with three areas of breakouts within and along the flow-field margins. The three main areas of breakouts were the 21 February breakout on the flank of Pu'u 'O'o, the 9 March breakout near the forested cone of Kahauale'a (burning trees were visible), and a relatively small forked breakout 5-6 km farther NE of Pu'u 'O'o. The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. During an overflight on 3 April geologists observed a small collapse pit had formed sometime since the previous overflight (possibly on 18 March based on tilt data) in the W portion of Pu'u 'O'o Crater. The opening was about 27 m in diameter but the chamber below was much larger. The floor of the collapse pit was about 80 m in diameter, about 24 m below the pit rim and hosted two active lava ponds.
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.