Report on Kilauea (United States) — 26 November-2 December 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 26 November-2 December 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, 26 November-2 December 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 26 November-2 December HVO reported that Kilauea’s 27 June NE-trending lava flow continued to be active. During an overflight on 1 December volcanologists observed a narrow lava flow that had originated from the W edge of the flow field and traveled 2.8 km N, burning vegetation along its path. They noted that weak surface activity was present in three areas upslope: the W side of the flow field that had produced the new lava flow, the E edge of the crack system, and at a breakout 3.5 km upslope of Pu'u 'O'o. They also measured a cross-sectional area of the lava stream within a tube near Pu'u 'O'o and found a 25% reduction in area compared to the previous week. The result was consistent with less lava flowing through the tube due to the summit deflation, which has been ongoing since 29 November.
The circulating lava lake occasionally rose and fell in the deep pit within Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of tephra 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.
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.