ALBERT

Beschreibung: The discovery that orbital variations are the driving force behind Quaternary climate change provides an impetus to set local and regional records of environmental change into the global context, a principle that has been strongly embraced by Quaternary scientists working in New Zealand. Their major achievements and significant current initiatives are reviewed here. The importance of the New Zealand Quaternary stems from its geographical context: a climatically sensitive, remote oceanic, southern location spanning 17 degrees of the mid-latitudes; an obliquely convergent plate boundary setting resulting in a high mountain range athwart the prevailing westerlies, active volcanism, a youthful and dynamic landscape, and mountains high enough to maintain glaciers today; and a remarkably short prehistory. The resultant records show marked environmental changes due not only to climatic oscillations but also to vigorous, active tectonism and volcanism. The Taupo Volcanic Zone, containing the world's strongest concentration of youthful rhyolitic volcanoes, has produced at least 10 000 km3of magma in the last 2 Ma. Climatic interpretations of records from marine sediments in the New Zealand region, together with several long sequences of alternating marine and terrestrial sediments, indicate broad synchrony with Northern Hemisphere events (within limitations of dating), although there are differences in detail for shorter-term climatic events. It is not yet certain that glacial advances coincided precisely with those in the Northern Hemisphere or were of similar duration. Late Cainozoic glaciation commenced c. 2.6-2.4 Ma but the record of glacial deposits is fragmentary and poorly dated except for the most recent events. The Last (Otira) Glaciation, from c. 100-10 ka, was characterized by at least five glacial advances including during the Last Glacial Maximum from 25 to 15 ka, when snowlines fell by 600-800 m. New Zealand evidence for cooling during the Younger Dryas stade is equivocal whilst isotopic records from speleothems, and other data, indicate warmer and wetter conditions from 10-7 ka, broadly conforming with records from mid-latitude Northern Hemisphere locations. Future advances will require sampling at shorter timescales, improvements in the accuracy and precision of existing dating methods and the development of new ones, extension of palaeoecological techniques to cover the full potential of new Zealand's diverse biota, and a stronger emphasis on quantification of palaeoclimatic parameters.

Beschreibung: 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.

Beschreibung: Remote sensing has demonstrated wide applicability in the area of estimating and mapping forest physical and structural features. Focus in recent years has been directed towards measuring the biophysical/physiological character of forest ecosystems in order to estimate and predict forest ecosystem health and sustainability. The following reviews the relationship between forest condition and reflectance; remote-sensing measurements (and derivatives) that provide biophysical/physiological information; and the potential of hyperspectral sensors in the measurement of these parameters.