Report on Kilauea (United States) — 17 September-23 September 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 17 September-23 September 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Kilauea (United States). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 17 September-23 September 2014. Smithsonian Institution and US Geological Survey.
19.421°N, 155.287°W; summit elev. 1222 m
All times are local (unless otherwise noted)
During 17-23 September HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas; smaller particles may have been dropped several kilometers away. At Pu'u 'O'o Crater, glow emanated from several outgassing openings in the crater floor. Two small lava ponds in the S pit were visible during the earlier part of the week, and small breakout flows near the crater burned adjacent forest.
The NE-trending lava flow had advanced at an average rate of 290 m/day between 15 and 17 September and 190 m/day between 17 and 19 September, and continued to cause localized fires as it spread through the forest. By 22 September the flow extended 16.4 km from the vent (measured in a straight line), placing the active flow front within the NW portion of the Kaohe Homesteads, a vacant forested portion of the subdivision. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Warning.
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.