Prefacing unexplored archives from Central Andean surface-to-bedrock ice cores through a multifaceted investigation of regional firn and ice core glaciochemistry.

• Autor(a) principal: Clifford, Heather M.
• Data de Publicação: 2023
• Outros Autores: Potocki, Mariusz, Rodda, Charles, Dixon, Daniel A., Birkel, Sean, Handley, Michael, Korotkikh, Elena, Introne, Douglas, Carlos, Franciéle Schwanck, Tavares, Flavia Alves, Bernardo, Ronaldo T., Lindau, Filipe Gaudie Ley, Gomez, Oscar Vilca, Jara-Infantes, Harrison, Bustínza Urviola, Victor, Perry, L. Baker, Maurer, Jonathan, Seimon, Anton, Schwikowski, Margit, Casassa, Gino
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/264341
• topic: Mudanças climáticas; Glacioquímica; Testemunhos de gelo; Vilcanota, Cordilheira (Peru); Real, Cordilheira (Bolívia); Climate change; Glaciological instruments and methods; Ice chemistry; Ice core; Mountain glaciers

Shallow firn cores, in addition to a near-basal ice core, were recovered in 2018 from the Quelccaya ice cap (5470 m a.s.l) in the Cordillera Vilcanota, Peru, and in 2017 from the Nevado Illimani glacier (6350 m a.s.l) in the Cordillera Real, Bolivia. The two sites are ~450 km apart. Despite meltwater percolation resulting from warming, particle-based trace element records (e.g. Fe, Mg, K) in the Quelccaya and Illimani shallow cores retain well-preserved signals. The firn core chronologies, established independently by annual layer counting, show a convincing overlap indicating the two records contain comparable signals and therefore capture similar regional scale climatology. Trace element records at a ~1?4 cm resolution provide past records of anthropogenic emissions, dust sources, volcanic emissions, evaporite salts and marine-sourced air masses. Using novel ultra-high-resolution (120 ?m) laser technology, we identify annual layer thicknesses ranging from 0.3 to 0.8 cm in a section of 2000-year-old radiocarbon-dated near-basal ice which compared to the previous annual layer estimates suggests that Quelccaya ice cores drilled to bedrock may be older than previously suggested by depth-age models. With the information collected from this study in combination with past studies, we emphasize the importance of collecting new surface-to-bedrock ice cores from at least the Quelccaya ice cap, in particular, due to its projected disappearance as soon as the 2050s.