Report on Kilauea (United States) — 20 April-26 April 2011
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 20 April-26 April 2011
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2011. Report on Kilauea (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 20 April-26 April 2011. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 20-26 April, HVO reported that activity at Kilauea continued from the summit caldera and from Pu'u 'O'o crater. The level of the circulating lava-pool surface in a deep pit below the Halema'uma'u crater floor periodically fluctuated. A gas plume from the vent drifted mostly SW, and deposited very small amounts of ash nearby. At Pu'u 'O'o crater, central sources continuously erupted lava within a perched lava lake that was approximately half the diameter of the crater floor. The lava level fluctuated within the lake walls and episodically overflowed the rim. During 23-24 April lava from several central sources buried most of the perched lake and covered the crater floor. During 24-25 April several large draining events were characterized by a drop in the new lava-lake surface by several meters and minor collapses of the lake's rim.
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.