Report on White Island (New Zealand) — 15 November-21 November 2000
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 15 November-21 November 2000
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2000. Report on White Island (New Zealand). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 15 November-21 November 2000. Smithsonian Institution and US Geological Survey.
37.52°S, 177.18°E; summit elev. 321 m
All times are local (unless otherwise noted)
A slight increase in activity occurred during the week, with steam-and-gas emissions and a loud noise from the active MH vent. By 16 November a small new vent SE of the MH vent was also steaming. The increase in activity was not accompanied by any significant seismic activity. White Island is at Alert Level 1 (ranging from 0 to 5).
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.