Report on Kilauea (United States) — 5 December-11 December 2018
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 5 December-11 December 2018
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2018. Report on Kilauea (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 5 December-11 December 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 lava at Kilauea’s Fissure 8 cone was last visible on 4 September, signaling the end of the Lower East Rift Zone (LERZ) eruptive phase. Consequently, the end of the LERZ eruption also marks the end of the over-arching, on-going eruption at Kilauea that began at the East Rift Zone (ERZ) in 1983. That determination was made by HVO in part by using the Global Volcanism Program guideline that an eruption should be considered over on the date of the last eruptive activity, and when there has not been renewed activity in the following three months.
HVO noted that geophysical data continued to show magma being supplied to Kilauea, including the refilling of the middle ERZ, and reminded the public that Kilauea remains an active volcano. As of 4 December the Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.
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.