Report on Kilauea (United States) — 14 April-20 April 2010
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 April-20 April 2010
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2010. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 14 April-20 April 2010. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 14-20 April activity reported by HVO at Kilauea was continuing at the summit and the east rift zone. At the summit, episodic rising and falling of the lava column continued at the deep pit inset within the floor of Halema`uma`u crater. Cycles occurred every 10-20 minutes until becoming more sporadic the evening of 14 April. On 15-16 April there were only 1-2 cycles/day. Activity increased again on the 17th, with cycles every 10-30 minutes. Glow from the vent was visible when the rising and falling cycles were frequent. On most mornings the plume of gas and ash from the summit vent drifted SW, depositing small amounts of tephra near the vent. Sulfur dioxide emission rates measured at the summit on 12, 14, 15, and 19 April were in the 600-790 tonnes/day range.
At the east rift zone, lava flowed through tubes to supply surface flows that advanced down the Pulama pali towards the coastal plain; on 16 April those flows were within 300 m of the coastal plain. Sulfur dioxide emission rates from the summit and east rift zone vents remained elevated. Geologists in the field on 17 April reported that the flow front had reached the E margin of the older Thanksgiving Eve Breakout (TEB) flow field on the coastal plain. On 19 April the flow front headed SE along the east margin of the TEB flow field, just W of the end of the Kalapana access road, and was 380 m NW of the viewing area.
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.