Report on Kilauea (United States) — 13 July-19 July 2011
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 13 July-19 July 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, 13 July-19 July 2011. 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 two lava lakes at Kilauea were active during 13-19 July. The level of the summit lava lake fluctuated deep in the 150-m-diameter vent inset within the E wall of Halema'uma'u Crater and circulated with various patterns. Spattering occurred at locations along the edge of the lake. Periodic measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby.
The preliminary sulfur dioxide emission rate from all of the east rift zone sources was 1,500 tonnes/day on 12 July, the highest emission rate since the end of the Kamoamoa eruption in early March. At Pu'u 'O'o, lava from vents near the NE edge and, to a lesser degree, along the W edge of the perched lava lake in the center of the crater floor continued to fill the lake. The lake level fluctuated and flowed through rim breaches, sending lava onto the Pu'u 'O'o crater floor. The near-vertical rim of the perched pond continued to be uplifted until through 17 July; the crater floor and perched lake rims formed a nearly-continuous ramp sloping away from the lake. The lava lake surface of the perched lava lake was elevated about 6 m higher than the surrounding crater floor and the rim was a few meters higher than the surface; the crater floor was 19 m below the E crater rim. Since the last measurements on 29 June, the crater floor had been uplifted about 1 m per day.
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.