Widespread persistence of expanded East Antarctic glaciers i

Details of Research

TitleWidespread persistence of expanded East Antarctic glaciers in the southwest Ross Sea during the last deglaciationAbstractIt has been suggested that the grounding line of the Last Glacial Maximum (LGM) ice sheet in the Ross Sea, Antarctica, receded in an approximately north-to-south pattern during the Holocene. An implication of this hypothesis is that geological evidence from the southwestern Ross Sea has been used widely to interpret retreat histories of the West Antarctic Ice Sheet (WAIS) across the wider Ross Sea embayment. Accurately constraining the timing and pattern of marine-based ice sheet retreat in this embayment is critical to understanding the drivers that may have triggered this event, and its contribution to rapid sea-level rise events. Here, we present new multibeam swath bathymetry data that identifies well-preserved glacial features indicating that thick (> 700 m) marine-based ice derived from the East Antarctic Ice Sheet coastal outlet glaciers dominated the ice sheet input into the southwestern Ross Sea during the last phases of glaciation. Subglacial geomorphic features indicate that ice derived from present outlet glacier valleys in South Victoria Land flowed southeastward. This is more consistent with flowlines from model-based interpretations of an earlier retreat of the WAIS in the central Ross Sea than with previous land-based geological reconstructions. This implies that coastal records of deglaciation along the Transantarctic Mountains front record only the final phases of glacial retreat in the Ross Sea. Therefore, chronological data from the central embayment are required to accurately constrain the timing of large-scale glacial retreat in the Ross Sea and to identify the mechanisms that drove it. © 2017 Geological Society of America.AcknowledgementsWe thank the crews of R/V Araon for their support, and reviewers for comments that improved the manuscript. This research was a part of the project titled "KIFES (KOPRI, PM 16060)" funded by the Ministry of Oceans and Fisheries (Korea), and the Korea Polar Research Institute (KOPRI) project PE17030. New Zealand funding was provided by Royal Society Rutherford Discovery Fellowship and Marsden Fund (RDF-13- VUW-003; 15-VUW-131), and MBIE (C05X1001).Funding DetailsKOPRI, Korea Polar Research Institute; MOF, Ministry of Oceans and Fisheries

Details

1st AuthorLee, J.AuthorLee, J.McKay, R.Golledge, N.Yoon, H.Yoo, K.-C.Kim, H.Hong, J.Year2017JournalGeologyVolume45Number5Pages403-406DOI10.1130/G38715.1URLhttps://www.scopus.com/inward/recor.....3db548c2498702c1eae9a591dKeywordsAcoustic variables measurementGeologyGlacial geologyGlaciersSea level, Chronological datumEast antarctic ice sheetsIce-sheet retreatLast deglaciationLast Glacial MaximumModel-based OPCSwath bathymetryWest antarctic ice sheets, Ice

Other

TypeArticleCitationLee, J., McKay, R., Golledge, N., Yoon, H., Yoo, K.-C., Kim, H. and Hong, J. (2017). Widespread persistence of expanded East Antarctic glaciers in the southwest Ross Sea during the last deglaciation. Geology, 45(5): 403-406