Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 5 October-11 October 2011
Managing Editor: Sally Sennert
Please cite this report as:
Global Volcanism Program, 2011. Report on Kīlauea (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 5 October-11 October 2011. Smithsonian Institution and US Geological Survey. https://volcano.si.edu/showreport.cfm?gvpvar=GVP.WVAR20111005-332010
During 5-11 October, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kīlauea's Halemaʻumaʻu crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby.
At the E rift zone, the fissure that formed on 21 September on the upper E flank of Puʻu ʻŌʻō continued to feed slowly-advancing lava flows to the NE and SE of the fissure. During the beginning of the week, overall activity within and SE of Puʻu ʻŌʻō Crater had slowed; only a few lava patches were visible in webcams. During 7-8 October lava began to flow from a vent at the E end of the crater floor and from an area at the W end the next day. Lava flows from the E-end source stalled on 10 October.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Geological Summary. Kīlauea overlaps the E flank of the massive Mauna Loa shield volcano in the Island of Hawaiʻi. Eruptions are prominent in Polynesian legends; written documentation since 1820 records frequent summit and flank lava flow eruptions interspersed with periods of long-term lava lake activity at Halemaʻumaʻu crater in the summit caldera until 1924. The 3 x 5 km caldera was formed in several stages about 1,500 years ago and during the 18th century; eruptions have also originated from the lengthy East and Southwest rift zones, which extend to the ocean in both directions. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1,100 years old; 70% of the surface is younger than 600 years. The long-term eruption from the East Rift Zone between 1983 and 2018 produced lava flows covering more than 100 km2, destroyed hundreds of houses, and added new coastline.