Report on White Island (New Zealand) — February 1989
Scientific Event Alert Network Bulletin, vol. 14, no. 2 (February 1989)
Managing Editor: Lindsay McClelland.
White Island (New Zealand) January crater emits ash; new vents eject blocks
Please cite this report as:
Global Volcanism Program, 1989. Report on White Island (New Zealand). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 14:2. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198902-241040.
37.52°S, 177.18°E; summit elev. 321 m
All times are local (unless otherwise noted)
The new R.F. Crater, first observed 12 January, had enlarged to about the same size as Congress Crater when geologists visited the volcano 1 February. R.F. Crater emitted a pink-brown ash column, while the previously active Hitchhiker vent was dormant. Ejecta from the new crater was dominated by altered lithic material with a very small proportion of fresh vesiculated glass.
An apparently brief diversion of heat flow to a zone of thermal features (Blue Duck area) ~80 m E of 1978 Crater formed at least two new fumarolic vents (N of Donald Mound). The largest new vent, first noticed by tourists on 29 January, was 15-20 m in diameter and surrounded by an apron of block-sized ejecta that extended ~50 m, with isolated impact craters to 150 m. Its temperature was 630°C on 1 February.
The explosion that formed the new vent was apparently much larger than those that formed the 1980 pits, and larger than any explosion that has occurred on the main crater floor in 20 years. A new linear zone of fumaroles, ~20-30 m long and trending ENE, had also formed NE of the Blue Duck fumaroles.
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.
Information Contacts: B. Scott, NZGS Rotorua.