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Cambridge NERC Doctoral Training Partnerships

Graduate Research Opportunities
 

Lead Supervisor: Liz Thomas, British Antarctic Survey

Co-Supervisors: Eric Wolff, Earth Sciences

Importance of the area of research concerned: 
The Antarctic ice sheet is the largest reservoir of freshwater on the planet, even small changes to its volume have global consequences. Accelerated melting of Antarctic glaciers contributes to global sea levels, however reconstructions using ice cores [1] demonstrated that snowfall has a mitigating effect [2]. More data is urgently needed from coastal regions (especially West Antarctica), and from mid and low latitudes glaciers that are currently in decline. Ice cores from these regions are subject to surface melt, believed to wash away valuable climate information [3], however, preliminary studies from the Sub-Antarctic Islands suggest this is not always the case. This project will establish the role of surface melt in preserving paleoclimate information and develop a method of extracting past snowfall from low elevation, coastal and mid-latitude ice cores. Providing accurate reconstructions of past and present surface mass balance essential in constraining predictions of future sea level rise.
Project summary : 
We investigate the impact of surface melting on ice cores, utilizing records from the sub-Antarctic islands, the Antarctic Peninsula and West Antarctica. The project is not dependent on the collection of new ice cores; however we will endeavour to include the student in future drilling projects. Pore and ice structure will be measured in 3D, using a unique X-ray-microfocus computer tomograph (micro CT), to determine the influence of melt water on pore size and how this alters the chemical and isotopic species in the ice. CT scans will be compared with existing chemistry data, analysed using continuous flow analysis (CFA) and new high-resolution chemistry data obtained using ion chromatography.
What will the student do?: 
Based at BAS the student will cut, analyse and interpret ice core data, working closely with researches from BAS and Earth Sciences. The micro CT measurements will be performed at the Alfred Wagner Institute (AWI) in Germany during two laboratory exchanges. In addition to developing the micro-CT analysis method, the project involves chemical measurements using ion chromatography and stable water isotope analysis. The data will be used to calculate past snowfall and other climate parameters at unique locations. The project requires considerable time in the -20C cold laboratories at both BAS and AWI and time working in a class-100 clean laboratory.
References: 
[1] Thomas, E. R., et al., 2017. Regional Antarctic snow accumulation over the past 1000 years. Climate of the Past, 13. 1491-1513. 10.5194/cp-13-1491-2017
[2] Medley, B., Thomas, E.R.. 2019. Increased snowfall over the Antarctic Ice Sheet mitigated twentieth-century sea-level rise. Nature Climate Change, 9. 34-39. 10.1038/s41558-018-0356-x
[3] Koerner, R. M. 1 997. Some comments on climatic reconstructions from ice cores drilled in areas of high melt. Journal of Glaciology.,43 (143), 90-97.
Applying
You can find out about applying for this project on the British Antarctic Survey (BAS) page.