Report on Kilauea (United States) — May 1983
Scientific Event Alert Network Bulletin, vol. 8, no. 5 (May 1983)
Managing Editor: Lindsay McClelland.
Kilauea (United States) Incandescent vents, harmonic tremor, and dilation across fissure system continue, then lava extrusion resumes
Please cite this report as:
Global Volcanism Program, 1983. Report on Kilauea (United States) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 8:5. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198305-332010.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
"Although Kilauea did not erupt during May, the fissure system for the 1983 E rift zone eruption was still active. Incandescent fissures with temperatures around 800°C were present at both vents that erupted from 28 March to 9 April (08:3-4). Steady slow dilation, averaging slightly less than 1 mm/day, was measured across the fissure system from Pu'u Kahaualea (near active vents about 17 km E of the summit caldera rim). Weak harmonic tremor continued throughout the month. These data suggest that slow intrusion was sustaining the feeder, and resumption of eruptive activity is possible."
Addendum: Eruptive activity accompanied by gradually increasing harmonic tremor resumed at about 0800 on 13 June, from the 28-30 March vent (near Pu'u Kamoamoa) about 15 km ESE of the summit caldera rim. Lava fountains 20-30 m high fed a flow that moved SE over the 28-30 March lava, along the Hawaii Volcanoes National Park boundary. The summit tiltmeter showed a deflation rate of 1 µrad per 6 hours. Moderately high and very steady harmonic tremor was recorded in the vicinity of the vent as the eruption continued 14 June.
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.
Information Contacts: R. Decker, E. Wolfe, A. Okamura, R. Koyanagi, and J. Nakata, HVO.