Holocene relative sea-level changes and ice fluctuations in the South Shetland Islands

Determining the nature and timing of glacial and climate fluctuations in Antarctica relative to those in the rest of the Southern Hemisphere is prerequisite for understanding the role of the southern high latitudes in climate change. Here, I present relative sea-level data from the South Shetland Islands (62–63°S, 58–61°W) that bear on the timing of Holocene deglaciation and subsequent ice fluctuations. Radiocarbon dates from raised beach sediments indicate that the 18–21 m elevation beach that marks marine limit dates to ~ 7000 cal yr B.P. However, limited evidence from stratigraphic sections and lake cores suggests that initial deglaciation may have occurred more than 2000 yr earlier. Rather than showing an exponential shape, typical of other Antarctic sites, the relative sea-level record of the South Shetland Islands is complex and characterized by what appear to be transgressions at ~ 6000–7000 and ~ 400 cal yr B.P. These transgressions may have been linked to glacial advance.