Report on Whakaari/White Island (New Zealand) — 23 October-29 October 2019
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 23 October-29 October 2019
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2019. Report on Whakaari/White Island (New Zealand) (Sennert, S, ed.). Weekly Volcanic Activity Report, 23 October-29 October 2019. Smithsonian Institution and US Geological Survey.
37.52°S, 177.18°E; summit elev. 294 m
All times are local (unless otherwise noted)
GeoNet reported that sulfur dioxide emissions and the level of volcanic tremor both increased at White Island over the past several months, and were at the highest levels since 2016. The report noted that the changes could be related to a variety of processes, including an increased level of unrest, though the level of hazards on the island remained unchanged; the Volcanic Alert Level remained at 1 (the second lowest level on a 0-5 scale) and the Aviation Color Code remained at Green. The crater lake level continued to rise and impact surface activity around vents, creating small-scale geysering, on the W side of the crater floor.
Geological Summary. The uninhabited Whakaari/White Island 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 SE side of the crater is open at sea level, with the recent activity centered about 1 km from the shore close to the rear crater wall. Volckner Rocks, sea stacks that are remnants of a lava dome, lie 5 km NW. Descriptions of volcanism since 1826 have included intermittent moderate phreatic, phreatomagmatic, and Strombolian eruptions; activity there also forms a prominent part of Maori legends. The formation of many new vents during the 19th and 20th centuries caused 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. The official government name Whakaari/White Island is a combination of the full Maori name of Te Puia o Whakaari ("The Dramatic Volcano") and White Island (referencing the constant steam plume) given by Captain James Cook in 1769.