Report on Kilauea (United States) — 13 June-19 June 2018
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 13 June-19 June 2018
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2018. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 13 June-19 June 2018. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Overlook Crater within Halema`uma`u Crater continued during 13-19 June. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline where the fast-moving flow entered the ocean in the area of the former Kapoho Bay. Minor lava activity at Fissures 16/18 was occasionally noted, and spattering was visible at Fissure 6 on 16 June. Hawai‘i County Civil Defense reported that by 17 June a total of 533 homes had been destroyed due to lava flows.
Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Steam plumes rose from areas in the crater as well as from circumferential cracks adjacent to the crater. Summit explosions occurred daily, producing ash plumes that rose as high as 3 km (10,000 ft) a.s.l. On 18 June residents reported feeling a large earthquake at 0613 and hearing roaring. The event was followed by an ash plume rising to 1.5 km (5,000 ft) a.s.l.
Fountaining at Fissure 8 was stable; lava fountains rose as high 60 m from a 52-m-high spatter cone. Pele's hair and other volcanic glass from the fountaining fell within Leilani Estates. The fountains continued to feed the fast-moving lava flow that traveled NE, and then SE around Kapoho Crater, and into the ocean. Occasional overflows sent small flows down the sides of the channel. Lava entering the ocean built a lava delta that by 16 June was just over 130 hectares in area. A plume of laze rose from the entry points. An area of thermal upwelling in the ocean out from the visible lava-delta front was visible, suggesting lava flowing on the ocean 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.