Report on Kilauea (United States) — 24 July-30 July 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 24 July-30 July 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, 24 July-30 July 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 24-30 July HVO reported that the circulating lava lake occasionally 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 receded during 25-26 July and was 75 km below the Halema'uma'u Crater floor on 26 July. The inner ledge, a long-time fixture within the vent, started collapsing at 2030 on 25 July; several pieces of the pit wall fell into the lake on both days. The lake level started to rise again and was 65 and 67 m below the crater floor on 28 and 29 July, respectively.
At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. The Kahauale’a 2 lava flow branches, fed by the NE spatter cone, were active as far NE as 3.2 km and as far NW as 2 km, and burned forest in two locations at the N edge of the 1983-1986 'a'a flows from Pu'u 'O'o. Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, and an ocean entry outside of the National Park boundary to the E.
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.