Marine Science Faculty Publications
Document Type
Article
Publication Date
2019
Keywords
Cryospheric science, Palaeoclimate
Digital Object Identifier (DOI)
https://doi.org/10.1038/s41598-019-50897-4
Abstract
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, particularly after the 1700s is linked to a positive Southern Annular Mode (SAM). We argue that a positive SAM drove stronger westerly winds, atmospheric warming and surface ablation on the eastern Antarctic Peninsula whilst simultaneously entraining more warm water into the Weddell Gyre, potentially increasing melting on the undersides of ice shelves. A possible implication of our data is that ice shelves in this region have been thinning for at least ~300 years, potentially predisposing them to collapse under intensified anthropogenic warming.
Rights Information
This work is licensed under a Creative Commons Attribution 4.0 License.
Was this content written or created while at USF?
Yes
Citation / Publisher Attribution
Scientific Reports, v. 9, art. 14606
Scholar Commons Citation
Dickens, W. A.; Kuhn, G.; Leng, M. J.; Graham, Alastair G. C.; Dowdeswell, J. A.; Meredith, M. P.; Hillenbrand, C.-D.; Hodgson, D. A.; Roberts, S. J.; Sloane, H.; and Smith, J. A., "Enhanced Glacial Discharge from the Eastern Antarctic Peninsula since the 1700s Associated with a Positive Southern Annular Mode" (2019). Marine Science Faculty Publications. 1580.
https://digitalcommons.usf.edu/msc_facpub/1580
