Report on Kilauea (United States) — 28 April-4 May 2010
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 28 April-4 May 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, 28 April-4 May 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 28 April-4 May HVO reported that activity at Kilauea continued at the summit and the east rift zone. At the summit, episodic rising and falling of the lava-pool surface continued at the deep pit inset within the floor of Halema`uma`u crater; glow from the vent was visible. On most mornings the plume of gas and ash from the summit vent drifted NW, W, and SW. On 29 April small rockfalls disrupted the surface of the pond, producing "dusty" plumes. Sulfur dioxide emission rates measured at the summit during 28-29 April were in the 800-1,000 tonnes/day range.
At the east rift zone, lava flowed through tubes to supply a surface flow that had advanced down the Pulama pali, onto the coastal plain, heading S, and reached the ocean on 29 April. Lava continued to flow into the ocean, just W of the "old" coastal viewing area during the rest of the reporting period. Lava also flowed along the E margin, between the highway and the coast. Incandescence was sometimes seen from a vent low on the S wall of Pu'u 'O'o crater.
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.