Agenda

Pascal Bohleber, 1Institute of Environmental Physics, Heidelberg University, Germany and Institute for Interdisciplinary Mountain Research, Austrian Academy of Sciences, Innsbruck, Austria

Abstract:
After first pioneering efforts more than a decade ago, Laser-Ablation Inductively-Coupled Plasma Mass Spectrometry (LA-ICP-MS) has recently started to re-emerge for glacio-chemical analysis of ice cores. Being an essentially non-destructive technique offering up to micron-scale depth resolution, LA-ICP-MS succeeds where conventional cm-resolution melting techniques fail: For analyzing highly thinned layers and abrupt changing signals in ice cores. Accordingly, LA-ICP-MS promises to play a key role in the next generation of deep ice coring projects,e.g. targeting to retrieve "the Oldest Ice", a 1.5 million year old record from Antarctica. As in any ice core, the oldest ice comprises the most highly thinned layers, and hence requires unprecedented detail in analysis. Here I will present recent advances made in exploring LA-ICP-MS for ice core impurity analysis, addressing challenges connected to calibration, quantifying depth-resolution and spatial variability.In a recent project we used thinned layers in an alpine ice core to perform a direct comparison of LA-ICP-MS with state-of-the-art continuous flow analysis. The comparison resulted in an important validation of the LA-ICP-MS signals and demonstrated how millimeter-scale annual layers can be identified, also in polar ice. Thefundamentalknow-howabout the novel high-resolution signals shows how misinterpretation can be avoided and reveals key issues on how to further improve the method for ice cores. To outline future research directions, I will include spotlights of my upcoming Marie Curie fellowship with Prof. Carlo Barbante, aiming at taking the next step in high-resolution ice core analysis by LA-ICP-MS.