A 2000 Year Saharan Dust Event Record From a European Alps Ice Core

• Main Author: Clifford, Heather
• Format: Text
• Language: unknown
• Published: DigitalCommons@UMaine 2019
• Subjects: Climate; Allan Hills; Antarc*; Antarctica; ice core
• Online Access: https://digitalcommons.library.umaine.edu/etd/3031; https://digitalcommons.library.umaine.edu/context/etd/article/4107/viewcontent/Clifford_Final_5.6.2019.pdf

Ice core archives provide the most direct and detailed evidence of past climate and atmospheric conditions, however, traditional ice core sampling (~1-cm resolution) does not provide significant environmental detail in low accumulation and compressed ice core sites. Advances in ice core sampling techniques allows for the capability to detect environmental signals in compressed ice found deeper in the core using finer sampling resolutions. Using the Climate Change Institute’s W.M. Keck Laser Ice Facility non-destructive, ultra-high-resolution, continuously sampled laser ablation-inductively coupled plasma-mass spectrometer (LA-ICP-MS) sampling on ice cores, we are able to resolve proxies for both climatological and meteorological scale events while preserving the core (Sneed et al., 2015). Ice-core analysis by LA-ICP-MS provides resolution (121-μm) necessary to achieve a robust measure of variability for select glacio-chemical species preserved in ice cores. Elements are measured using single element or multi-element line scans, producing a continuous, miniscule laser ablated profile along the length of the ice sample. We measure select glacio-chemical species using the LA-ICP-MS sampling technique for 20-m of the Colle Gnifetti ice core, drilled in the Swiss-Italian Alps, and ~0.7-m of the Allan Hills ice core, drilled in Antarctica. These two ice cores, though drilled at quite different locations, demonstrate the advantages of ultra-high-resolution sampling for ice core records. For the Allan Hills ice core, we can detect environmental signals and potentially annual layers at the depth ~125-m, which is established as an age of ~1-Ma old (Higgins et al., 2015). For the 2013 Colle Gnifetti ice core, we established a strong correlation between equivalent species from the LA-ICP-MS data and traditionally sampled ICP-MS and revealed climate proxies related to Saharan dust, Atlantic moisture, and anthropogenic inputs that can extend our understanding of air mass sources transported to the European Alps region over ...