Isotopic Composition of Surface Snow Across Antarctica: A Coast to Coast Survey

Partners: International Atomic Energy Agency; Yale University Department of Geology & Geophysics

The stable isotope composition of precipitation at high latitudes is affected by a number of geographical (e.g. elevation) and climate (e.g temperature) factors. Scientists can use the stable isotope composition of snow at certain depths to reconstruct climatic conditions at a particular time in the recent past (the relationship between isotopic composition and local temperature has also been applied to deep ice cores going hundreds of thousands of years into the past). Studying the relationship between stable isotope composition of precipitation and local climate is important in understanding the dynamics of the global water cycle, and is therefore fundamental to understanding climate change.

Many surface isotope surveys have been conducted in Antarctica, particularly through international collaborative research initiatives such as the International Transantarctic Scientific Expedition (ITASE), but there remains large parts of the continent that have not been studied. Our route covers 640km of unstudied territory between the South Pole and the Ross Ice Shelf. This leg of the journey has a large altitude range of around 8,500 vertical feet and passes over a glacier, through the Transantarctic Mountains, and over the Antarctic Plateau. As such, climatic variability may be highly localized.

Up to 10 snow pits will be created and sampled across the continent during the course of the expedition, ranging between one and four meters in depth (depending on the thickness of annual snow layers at each site). 25ml water equivalent in snow will be taken every 1cm. Each site will vary significantly in terms of the number of years studied. Up to 2,000 samples may be collected during the crossing.

Many of the samples will be sent to the International Atomic Energy Agency isotope hydrology laboratories in Vienna for analysis after the expedition. The resultant data will become a part of the Global Network of Isotopes in Precipitation (like data from Parker’s 2012 expedition to the North Pole) but will also contribute to other existing and new projects.