Report on Whakaari/White Island (New Zealand) — April 1991
Bulletin of the Global Volcanism Network, vol. 16, no. 4 (April 1991)
Managing Editor: Lindsay McClelland.
Whakaari/White Island (New Zealand) Renewed ash emission; new collapse pit
Please cite this report as:
Global Volcanism Program, 1991. Report on Whakaari/White Island (New Zealand) (McClelland, L., ed.). Bulletin of the Global Volcanism Network, 16:4. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199104-241040.
37.52°S, 177.18°E; summit elev. 294 m
All times are local (unless otherwise noted)
There was no evidence, during fieldwork 21 April, of eruptive activity since the 20-22 March eruption that formed Orca vent and was probably responsible for up to 10 mm of ash deposited on the 1978/91 Crater rim since 13 February. An increase in gas emission (compared to visits during February and March) was noted at Orca vent and TV1 Crater. . . . Intense gas emission also occurred from an area of hot ground NW of TV1.
Several morphologic changes were observed in the crater area. A second, smaller vent (~5 m in diameter) was found on the slope NW of Orca vent. A new collapse pit, ~20 m in diameter and 50 m deep, was located above the conduit that had previously fed Donald Duck Crater. The new pit, a few meters NW of the crater, looked fresh, suggesting that it had formed shortly before the 21 April visit.
Ash-laden steam emission reportedly began 23 April and was continuing as of 3 May. No significant volcanic tremor or other seismicity was recorded during this period.
Geologic Background. 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.
Information Contacts: I. Nairn and B. Scott, DSIR Geology & Geophysics, Rotorua.