Report on Kilauea (United States) — 21 February-27 February 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 21 February-27 February 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Kilauea (United States). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 21 February-27 February 2001. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
Lava continued to flow SE down the Pulama pali and across the coastal plain to within 1 km of the coast. At 1317 on 20 February a M 3.7 earthquake occurred that was centered about 5 km SE of Halemaumau Crater at a very shallow depth. Brief summit deflation occurred on 24 February, but ended the next day with no corresponding period of inflation following it. NE of Kilauea at Mauna Kea volcano, a swarm of earthquakes occurred during 22-24 February on Mauna Kea's NE flank. The earthquakes were all approximately M 3 and occurred at 2-12 km depth. Swarms occasionally occur in this area of Mauna Kea.
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.