Report on Kilauea (United States) — 26 March-1 April 2008
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 26 March-1 April 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, 26 March-1 April 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 and National Park Service (NPS) crews as well as web camera views, HVO reported that during 26 March-1 April lava flow activity from Kilauea's Thanksgiving Eve Breakout (TEB) shield was mostly concentrated at multiple points along the Waikupanaha and Ki ocean entries. Incandescence from the TEB vent was noted. During 25-26 March, an active lava flow was spotted SE of Kalalua Cone. Diffuse incandescence was seen on the web camera in Pu'u 'O'o crater.
During the reporting period, Kilauea summit earthquakes were located beneath Halema`uma`u Crater, beneath the summit to the W, along the S-flank faults, and along the SW and E rift zones. The eruption from the vent in Halema'uma'u Crater continued to produce brown ash plumes that turned white for periods of time on 27, 28, and 31 March and on 1 April. Analysis of ash from the white plumes revealed that there was more volcanic glass than ash from the brown plumes. The plumes drifted mostly SW. Incandescence was seen at the base of the plume during the night. During 29 March-1 April, incandescent fragments were ejected from the vent.
Sulfur dioxide emission rates from the summit area have been elevated at 2-4 times background values since early January. The emission rate fluctuated between 700-1,500 tonnes per day during 26-31 March, compared to a background rate of 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.