Abstract:
The climate of the Victoria Land Coast is created by the interacting influences of the Dry Valleys, East Antarctic Ice Sheet and the Ross Sea. Slight changes can significantly alter local weather patterns and as such a climate record of the area provides ideal opportunities to study rapid, high frequency climatic variations. International polar ice coring programmes (e.g. GISP and Vostok) have
... provided powerful new insights into Earth's climate back 400,000 years, from the diverse inventory of atmospheric information stored both within the ice and trapped air bubbles. To understand and predict the local response to anthropogenically induced global warming seen in these "global" ice cores, the focus of ice core research in Antarctica is moving to the acquisition of high-resolution regional paleoclimatic archives of annual-scale that overlap with and extend the instrumental records of the last 40 years back several thousand years. This has been a key motivation behind the US-led International Transantarctic Scientific Expedition (ITASE) of which New Zealand is a member.
The New Zealand project's objective is to recover a series of ice cores from glaciers along a 14-degree latitudinal transect of the climatically sensitive Victoria Land coastline and thereby directly contribute a critical dataset to ITASE. The NZ ITASE sites (including two sites at Victoria Lower Glacier, Baldwin Glacier, Wilson Piedmont Glacier, Polar Plateau, Evans Piedmont Glacier, Mt Erebus Saddle, Whitehall Glacier, Skinner Saddle and Gawn Ice Piedmont Glacier with future sites planned at Beardmore Glacier, Roosevelt Island, and coastal sites in West Antarctica) have been chosen to capture and quantify the steep climate gradients from the Scott Coast to the Polar Plateau, the local climate system of the McMurdo Dry Valleys, and the effect of altitude within the Transantarctic Mountains. Coastal sites are especially climate sensitive and show potential to archive local, rapid climate change events that are subdued or lost in the 'global' inland ice core records.
Investigation and datasets include: GPR/GPS surveying to map bedrock topography and internal glacial structure and glacier topography, firn and ice cores to quantify the variability of climate record with analysis of temperature, crystal structure, crystal geometry, density of the snow, melt, dust/tephra occurrence, gas content, porosity, gas bubble size and geometry, snow profiles were analysed for ion content, isotopic ratios, dust content, beta radioactivity, chemical properties and mineralogy to transfer functions with the meterological record, borehole temperature and light penetration, submergence velocity measurements to analyse the mass balance of the glaciers, meterological data and ablation measurements.