Report on White Island (New Zealand) — 2 January-8 January 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 2 January-8 January 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on White Island (New Zealand). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 2 January-8 January 2013. Smithsonian Institution and US Geological Survey.
37.52°S, 177.18°E; summit elev. 321 m
All times are local (unless otherwise noted)
On 7 January GeoNet Data Centre reported that the Aviation Colour Code for White Island was lowered to Yellow (second lowest on a four-color scale) and the Volcanic Alert Level was lowered to 1. A spiny lava dome in the crater formed on 5 August was first clearly observed on 10 December. Observations on 20 December indicated that the dome had not changed. Scientists visited the area on 1 January and again observed no changes. They measured temperatures of 200-240 degrees Celsius from the lava dome and 70-80 degrees from the nearby hot lake, and observed lots of gas coming from the lake. The report also indicated continuing elevated levels of tremor.
Geologic Background. Uninhabited 2 x 2.4 km White Island, one of New Zealand's most active volcanoes, is the emergent summit of a 16 x 18 km submarine volcano in the Bay of Plenty about 50 km offshore of North Island. The island consists of two overlapping andesitic-to-dacitic stratovolcanoes; the summit crater appears to be breached to the SE, because the shoreline corresponds to the level of several notches in the SE crater wall. Volckner Rocks, four sea stacks that are remnants of a lava dome, lie 5 km NNE. Intermittent moderate phreatomagmatic and strombolian eruptions have occurred throughout the short historical period beginning in 1826, but its activity also forms a prominent part of Maori legends. Formation of many new vents during the 19th and 20th centuries has produced rapid changes in crater floor topography. Collapse of the crater wall in 1914 produced a debris avalanche that buried buildings and workers at a sulfur-mining project.