Characteristics and sources of tephra layers in the EPICA-Dome C ice record (East Antarctica): Implications for past atmospheric circulation and ice core stratigraphic correlations

• Published in: Earth and Planetary Science Letters
• Main Authors: Narcisi, B, Petit, J, Basile Doelsch, I, DELMONTE, BARBARA, MAGGI, VALTER
• Other Authors: Delmonte, B, Maggi, V
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2005
• Subjects: Antarctica; ice core synchronization; vocanic activity; Antarc*; Antarctic; Antarctic Peninsula; East Antarctica; EPICA; ice core; Marie Byrd Land; South Atlantic Ocean
• Online Access: http://hdl.handle.net/10281/17863; https://doi.org/10.1016/j.epsl.2005.09.005

Thirteen discrete air-fall tephra layers were identified in the last 200,000-yr section of the EPICA-Dome C ice record drilled in the East Antarctic plateau (75°06′S, 123°21′E). Quantitative grain size, glass particle morphology, and the grain-discrete major element composition of the glass fraction of these layers were investigated. Through comparison with literature data on the rock composition of Quaternary volcanic centres located within and around Antarctica, five tephra layers were attributed to South Sandwich volcanoes in the South Atlantic Ocean, two to South Shetland volcanoes (northern Antarctic Peninsula), two to Andean volcanoes, and four to Antarctic (Marie Byrd Land and Melbourne) provinces. The abundance of layers originating in the southern part of the Atlantic confirms that westerly atmospheric circulation spiralling towards East Antarctica prevailed over the last 200 ka. Moreover, the record of events from Antarctic centres suggests that atmospheric trajectories from West to East Antarctica can also be significant. A few ash layers are geochemically distinct and appear equivalent to levels from Vostok and Dome Fuji deep ice records, located ca. 600 km and ca. 2000 km, respectively, from Dome C on the Antarctic plateau. These layers provide unambiguous markers for future correlation with other Antarctic ice cores and circumpolar marine climatic records. They also provide reliable constraints to get a common timescale by glaciological modelling, and represent a first step towards absolute ice core dating. © 2005 Published by Elsevier B.V.