Report on Kilauea (United States) — 11 March-17 March 2009
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 11 March-17 March 2009
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2009. Report on Kilauea (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 11 March-17 March 2009. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 11-17 March, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha ocean entry and occasionally producing explosions. Thermal anomalies noted during most days on the coastal plain suggested surface flows. During 11-13 March, scattered surface flows near the Prince lobe were noted. On 13 March, a 30-m-wide lava flow entered the ocean at Kupapa'u, a second ocean entry location to the W of Waikupanaha. Kupapa'u was active during 14-17 March.
The vent in Halema'uma'u crater continued to produce a predominantly white plume; southwesterly winds often caused poor air quality in communities to the N. Incandescence from the vent was seldom seen. On 12 March, seemingly fresh spatter was collected from bins placed near the plume; minimal amounts of ash were collected the next day. The sulfur dioxide emission rate at the summit was 1,000 tonnes per day on 13 March; the 2003-2007 average rate was 140 tonnes per day. Field visits to the caldera floor indicated that there was an ash emission event sometime before dawn on 15 March, possibly following a wall collapse within the Halema'uma'u vent. Ash coated several monitoring instruments and was detected in Volcano, about 6 km NE. On 16 March, the plume drifted N and dusted HVO with ash.
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.