Research on glaciers and snow in New Zealand

Abstract

The glaciers and snowfields of the Southern Alps of New Zealand are the most significant in the Southern Hemisphere outside Antarctica and South America. The most substantial data on Southern Hemisphere glacier fluctuations come from New Zealand. The nature and behaviour of New Zealand's glaciers are also of wider scientific interest, because they are highly sensitive, high input-output systems that represent the temperate, maritime end of the glacier process-behaviour continuum. The areal extent and volume of glaciers and snow are outlined and an assessment is made of their scientific relevance and of their importance as resources and hazards. The main themes and progress of research on glaciers and snow, including snow avalanches, are reviewed. Glacier research has concentrated on only a few key glaciers and has focused on understanding glacier change. Main topics covered in this review relate to this focus and include fluctuations in termini, other mass balance signals and response to climate variability. Research on mass balance processes, glacier dynamics and glacier hydrology is also outlined. Seasonal snow has received less attention until recently. The main emphasis has been on quantification and past variability and its contribution to river flow, particularly in the most important hydroelectric power catchments of the South Island. Some field measurements have been made of the energy balance over snow. Research on snow avalanches has grown as the demands of winter recreation and alpine tourism have increased the hazard. Research first concentrated on production of avalanche atlases for the most hazardous areas and on quantifying the nature of the hazard. Subsequently, there has been a shift towards more process studies that are related to avalanche formation and runout distance. The main gaps in research on glaciers and snow are identified and key areas for future work proposed. There is an urgent need, in particular, for glacier mass-balance measurements. Extensive data on snow structure need to be synthesized. Satellite imagery should be used for monitoring of seasonal snow. Snow melt during northwest storms needs to be better defined. A more developed engineering approach is required for the study of snow avalanches. New Zealand offers exciting possibilities for the study of cryospheric processes, including response to future climate change.