Report on Kilauea (United States) — 5 March-11 March 2008
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 5 March-11 March 2008
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2008. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 5 March-11 March 2008. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
Based on visual observations and web camera views when weather permitted, HVO reported that during 5-11 March lava flow activity from Kilauea's Thanksgiving Eve Breakout (TEB) shield was concentrated at rootless satellitic shields to the E and SE, in the Royal Gardens subdivision, and at two ocean entries. A lava flow from the rootless shield complex traveled E towards Kalalua. Earthquakes were located beneath Halema'uma'u crater, along the S-flank faults, beneath the summit, and along the SW rift zones.
During 4-6 March, the TEB flow expanded E above and within Royal Gardens, and also split into two 100-m-wide lobes (E and W) about 150 m N of the County access road. According to local sources, at about 2330 local time on 5 March the W lobe entered the ocean at the Waikupanaha entry, named for a nearby pond that was covered by lava in the 1990s. During 7-11 March, incandescence was visible from vents on top of two of the SE satellitic shields. On 8 March, the W lobe continued to build a delta; the E lobe was 470 m from the ocean. A public viewing area with excellent views of the pahoehoe flows opened. On 9 March, the Waikupanaha entry steamed from four points, but small streams of lava were only visible entering the ocean in the evening. The delta was 500 m wide and extended 100-150 m out into the ocean. During 9-10 March, smoke plumes and incandescence from Royal Gardens suggested that active breakouts from the tube system had possibly diminished the amount of lava arriving at the ocean. Diffuse incandescence was observed on the web camera in Pu'u 'O'o crater on 10 and 11 March.
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.