The Antarctic Peninsula's Response to Holocene Climate Variability: Controls on Glacial Stability and Implications for Future Change

• Main Author: Minzoni, Becky Lynn
• Other Authors: Anderson, John B, Droxler, André, Nittrouer, Jeffrey A, Rudolf, Volker
• Format: Thesis
• Language: English
• Published: 2015
• Subjects: Antarctica; Holocene climate; glacimarine sediment; polar diatoms; glacial stability; Amundsen Sea; Antarctic; Antarctic Peninsula; Croft; Ferrero Bay; The Antarctic; Antarc*; Ice cap; ice core; Ice Shelves; Sea ice
• Online Access: https://hdl.handle.net/1911/88211

The Antarctic Peninsula is one of the most rapidly changing regions in the Cryosphere, with 87% of its glaciers receding and several ice shelves catastrophically collapsing since observations began in the 1960’s. These substantial, well-documented changes in the ice landscape have caused concern for the mass balance of the Antarctic Peninsula Ice Cap. To better understand the significance of these recent changes, I have assimilated a massive database of new and published marine sedimentary records spanning the Holocene Epoch (the last 11.5 kyrs). The database includes 9 coastal embayments with expanded sedimentary packages and well-dated cores. Each site represents an end-member in the wide range of Antarctic Peninsula oceanography, orography, meteorology, and glacial drainage basin characteristics. Multi-proxy analysis, including sedimentology, geochemistry, and micropaleontology, was conducted at each site to reconstruct glacial history at centennial-scale resolution on par with ice-core data. The coastal sites were then compared in the context published ice-core paleoclimate, paleoceanographic, and glaciological records. The first of these sites, Herbert-Croft Fjord, provides an unparalleled opportunity to compare the marine sediment record with a related ice-core in an Antarctic maritime setting. Herbert-Croft Fjord is the southernmost embayment studied on the eastern side of the Antarctic Peninsula and represents an end-member with a cold, dry atmosphere and cold, saline ocean mass. The record from Herbert-Croft Fjord indicates grounded ice receded quickly and early in the Holocene, followed by a floating ice phase that collapsed 10 ± 2.4 calendar kyrs before present (cal kyr BP, where present day is 1950 A.D.) and never re-advanced. The fjord remained open and productive during the prolonged warm intervals of the Mid Holocene, and began to experience greater glacial influence and sea ice cover during Late Holocene cooling, a period termed the Neoglacial. The second site, Ferrero Bay of the Amundsen Sea, is ...