Report on Kilauea (United States) — 16 April-22 April 2008
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 16 April-22 April 2008
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2008. Report on Kilauea (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 16 April-22 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 observations during helicopter overflights, visual observations from HVO and National Park Service (NPS) crews, and web camera views, HVO reported that during 16-22 April lava flowed SE through a lava tube system underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex to the Waikupanaha ocean entries. The Ki ocean entry was inactive during 19-22 April. Occasionally, incandescence from breakouts along the lava-tube system was noted.
During the reporting period, Kilauea summit earthquakes were located beneath Halema'uma'u Crater, beneath Napau Crater, along the S-flank faults, and along the upper E and SW rift zones. The eruption from the vent in Halema'uma'u Crater continued to produce white ash plumes that drifted mainly SW. During most nights incandescence was seen at the base of the plume. On 16 April, a small explosion from the vent ejected ash onto the overlook parking lot and on a portion of Crater Rim drive. Seismic tremor was elevated.
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 870 and 1150 tonnes per day during 15-21 April, compared to a background rate of 150-200 tonnes 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.