Report on White Island (New Zealand) — 1 January-7 January 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 1 January-7 January 2020
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2020. Report on White Island (New Zealand). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 1 January-7 January 2020. Smithsonian Institution and US Geological Survey.
37.52°S, 177.18°E; summit elev. 294 m
All times are local (unless otherwise noted)
On 6 January GeoNet reported that White Island remained in an elevated state of unrest. Very hot steam and gas emissions continued to rise from the 9 December vents, causing incandescence to be recorded on near infrared cameras. Volcanic tremor decreased to low levels on 14 December 2019 and remained low. Sulfur dioxide emission rates were at normal levels. Continuing movement of the back-crater wall W of the 1914 landslide deposits was detected and will continue to be monitored. Small amounts of ash sometimes rose from the active vent due to wall collapses, as on 23 and 26 December. The Volcanic Alert Level remained at 2 and the Aviation Color Code was lowered to Yellow.
Geologic Background. The uninhabited White Island, also known as Whakaari in the Maori language, is the 2 x 2.4 km 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, sea stacks that are remnants of a lava dome, lie 5 km NW. Descriptions of eruptions since 1826 have included intermittent moderate phreatic, phreatomagmatic, and Strombolian eruptions; activity there 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. Explosive activity in December 2019 took place while tourists were present, resulting in many fatalities.