Under what climate conditions were the New Zealand subantarctic islands glaciated?

Mountain glaciers in the New Zealand subantarctic islands, particularly those in the Auckland and Campbell archipelagos, provide critical insights into past climate conditions. A study using a 2D glacier model reveals that these islands were glaciated under significantly cooler temperatures—6 to 7 °C below mid-20th century levels for recent glaciation and more than 8 °C lower for ice cap coverage, assuming present-day precipitation. The research also highlights the sensitivity of glacier mass balance to summer temperatures, with increased temperature seasonality requiring further reductions in temperature to achieve equivalent ice volumes. These findings refine our understanding of glaciation in the southwest Pacific sector of the Southern Ocean and offer a framework for evaluating global climate model simulations. However, precise dating of past glaciation events remains necessary to fully interpret the climatic implications.

Eaves, S., Anderson, B., & Gray, R. (2025). Under what climate conditions were the New Zealand subantarctic islands glaciated? Open Access Te Herenga Waka-Victoria University of Wellington. https://doi.org/10.25455/WGTN.30615029