Report on Whakaari/White Island (New Zealand) — 18 December-24 December 2019
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 18 December-24 December 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, 18 December-24 December 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 during 18-23 December the level of volcanic tremor at White Island remained low and gas-and-steam plumes were strongly emitted from the new vent area. The highest-temperature emissions were more than 650 degrees Celsius measured during an overflight on 19 December. Volcanologists also measured about 1,300 tons/day of sulfur dioxide, slightly lower than 12 December measurements of about 1,730 tons/day. A small part of the SW slope of the 1914 landslide (inside the crater rim and opposite the former viewing area) had collapsed into the crater lake and active vent area, leaving a scarp 12 m high. The area had been unstable prior to the 9 December eruption. According to the New Zealand Police the death toll from the 9 December eruption had reached 17. Two people remained missing; the search was suspended on 24 December.
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.