Enhanced glacial discharge from the eastern Antarctic Peninsula since the 1700s associated with a positive Southern Annular Mode. ...

• Main Authors: Dickens, WA, Kuhn, G, Leng, MJ, Graham, AGC, Dowdeswell, JA, Meredith, MP, Hillenbrand, C-D, Hodgson, DA, Roberts, SJ, Sloane, H, Smith, JA
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2019
• Subjects: 37 Earth Sciences; 3709 Physical Geography and Environmental Geoscience; 3702 Climate Change Science; 3705 Geology; Antarctic; Antarctic Peninsula; The Antarctic; Antarc*; Ice Sheet; Ice Shelf; Iceberg*
• Online Access: https://dx.doi.org/10.17863/cam.46832; https://www.repository.cam.ac.uk/handle/1810/299762

The Antarctic Peninsula Ice Sheet is currently experiencing sustained and accelerating loss of ice. Determining when these changes were initiated and identifying the main drivers is hampered by the short instrumental record (1992 to present). Here we present a 6,250 year record of glacial discharge based on the oxygen isotope composition of diatoms (δ18Odiatom) from a marine core located at the north-eastern tip of the Antarctic Peninsula. We find that glacial discharge - sourced primarily from ice shelf and iceberg melting along the eastern Antarctic Peninsula - remained largely stable between ~6,250 to 1,620 cal. yr BP, with a slight increase in variability until ~720 cal. yr. BP. An increasing trend in glacial discharge occurs after 550 cal. yr BP (A.D. 1400), reaching levels unprecedented during the past 6,250 years after 244 cal. yr BP (A.D. 1706). A marked acceleration in the rate of glacial discharge is also observed in the early part of twentieth century (after A.D. 1912). Enhanced glacial discharge, ...