Report on Kilauea (United States) — 20 February-26 February 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 20 February-26 February 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 20 February-26 February 2013. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 20-26 February HVO reported that the circulating lava lake periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. The lake level was 35 m below the Halema'uma'u crater floor on 20 February.
At Pu'u 'O'o Crater, glow emanated from spatter cones on the SE part of the crater floor, from a spatter cone at the NW edge of the floor, and from a perched lava lake on the NE part of the floor. Multiple lava flows from the NE spatter cone, collectively and informally called the Kahauale'a flow, traveled across the NE flank of Pu'u 'O'o cone to the cone's base and continued to advance NE and SW over older flows. Lava flows were active above the pali (5 km SE of Pu'u 'O'o) and in a 1-km-wide area on the coastal plain. To the W, a 350-m-wide lava flow advanced towards the coast and produced scattered breakouts. Web cameras recorded steam plumes from lava sporadically entering the ocean at multiple locations. A few small bench collapses may have occurred.
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.