RITA: Raman non-destructive Ice cores analysis of visible Tephra layers in Antarctica

Ice cores are exceptional archives of past climate change, preserving climate forcing factors and proxies of the climate system’s response. Among these, volcanic eruptions play a key role. Englacial tephras enable the reconstruction of explosive volcanism, offer insights into volcano–climate interactions and allow the correlation of paleoclimate records across distant regions, when the volcanic source is known. Deciphering the source of far-travelled volcanic products is challenging and requires analysis of the geochemical composition (major and trace elements) of volcanic glass within a given layer, compared with known volcanic sources. This task is further complicated by the broad range of potential source volcanoes and the compositional similarity of their eruptive products. In this context, volcanic minerals, although less commonly used than glass, represent a valuable complementary tool for source fingerprinting. More broadly, most analytical methods require melting ice cores, compromising both their preservation and future reuse. As climate change poses increasing threat to global ice reserves, the development of new techniques that address this limitation is of critical importance. Here, we present RITA, a novel, non-destructive Raman spectroscopy-based approach for the analysis of visible tephras layer directly on an ice core retrieved from Campbell Glacier, Antarctica (164.181° E, 74.283° S). The analyzed mineral assemblage is indicative of a highly alkaline volcanic source and shows strong geochemical affinity with published datasets tracing its provenance and effectively rules out alternative sources. These results confirm the effectiveness of the method while preserving ice core integrity and highlighting the technique’s potential for broader applications.