Marine record of Holocene climate, ocean, and cryosphere interactions: Herbert Sound, James Ross Island, Antarctica
Rebecca Totten Minzoni, John B. Anderson, Rodrigo Fernandez, Julia Smith Wellner
Quaternary Science Reviews, Volume 129, 1 December 2015, Pages 239–259
The sediment record offshore James Ross Island, northeast Antarctic Peninsula presents an unparalleled opportunity to directly compare marine and terrestrial climate records spanning the Holocene in maritime Antarctica. An 11 m drill core was collected between Herbert Sound and Croft Bay as part of the SHALDRIL NBP-0502 initiative and produced the southernmost sediment record from the eastern side of the AP. Thirty-eight radiocarbon ages are used to construct an age model of centennial-scale resolution. Multi-proxy records, including magnetic susceptibility, pebble content, particle size, total organic carbon, and diatom assemblages, were interrogated in the context of nearby Holocene-age ice core, lake, and drift records from James Ross Island. Differences in the timing and expression of Holocene events reflect marine controls on tidewater glaciers, such as water mass configurations and sea ice. Glacial behavior mimics ice core paleotemperatures during the Holocene, with the exception of distinct ocean warming events. Herbert Sound was fully occupied by grounded ice during the Last Glacial Maximum, and experienced rapid lift-off, followed by a floating ice phase. The canopy of floating ice receded by 10 ± 2.4 cal kyr BP, presumably in response to Early Holocene warming. Herbert Sound and Croft Bay fully deglaciated by 7.2 cal kyr BP, when the Mid Holocene Hypsithermal commenced and the sound became open and productive. An extreme peak in productivity ∼6.1 cal kyr BP indicates an oceanic warming event that is not reflected in atmospheric temperature or lacustrine sediment records. Increase in sea ice cover and ice rafting mark the onset of the Neoglacial ∼2.5 cal kyr BP, when pronounced atmospheric cooling is documented in the James Ross Island ice core. Our comparison facilitates more holistic understanding of atmosphere-ocean-cryosphere interactions that may aid predictions of glacial response to future warming and sea-level scenarios.