Report on Kilauea (United States) — 2 July-8 July 2008
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 2 July-8 July 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, 2 July-8 July 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 from HVO crews, video footage, pilot reports, and web camera views, HVO reported that during 2-8 July, lava flowed SE through a lava tube system from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex. The TEB vent is located a little over 2 km NE of Pu'u 'O'o crater. During 2-6 July, lava flows reached the Waikupanaha ocean entry and created a steam plume from contact with the water. Incandescence was also seen from surface lava flows at multiple breakout points along the lava tube system. On 7 July, seismic tremor levels near the TEB vent abruptly doubled, corresponding to a substantial new breakout in the rootless shield area. The steam plume at the Waikupanaha ocean entry was also absent that day and the next. An overflight revealed that a lava fountain from one of the breakouts on rootless shield 3 (about 1 km SE of the TEB vent) was 12-15 m high and fed several lava flows. The lava fountain and a lava pond were active during 7-8 July and incandescence at shield 6 (about 2 km SE of the TEB vent) was noted.
At Pu'u 'O'o the sulfur dioxide emission rate fluctuated between 3,100 and 4,800 tonnes per day when measured during 4-6 July; the average background rate is about 2,000 tonnes per day. Incandescence from two distinct sources in the E and W ends of Pu'u 'O'o crater was observed on the web camera during 4-6 July. Diffuse incandescence was noted during 7-8 July.
During the reporting period, Kilauea earthquakes were located beneath the summit area, along S-flank faults, along the E and SW rift zones, beneath Halema'uma'u crater, and beneath the area where the Koa'e fault system joins the upper E rift zone. Beneath Halema'uma'u crater, another 20-100 small earthquakes per day also occurred but were too small to be located. The vent in the crater continued to produce a white plume with minor ash content that drifted mainly SW. Night-time incandescence was seen at the base of the plume. The sulfur dioxide emission rate was high, between 700 and 1,400 tonnes per day, during 2-7 July. The pre-2008 background rate was 150-200 tonnes per day.
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.