Palaeoclimate reconstructions from the Antarctic Peninsula; linking marine and terrestrial records
Hey, Anna Rose
The Antarctic Peninsula (AP) is one of the fastest-warming regions on Earth. To assess whether this warming is part of the natural variability in the climate system, palaeoclimate archives are used to document the character of past climate changes and constrain predictions for the future. This investigation integrates a suite of radiocarbon dated marine sediment records from the continental shelf of the AP to provide a critical assessment of the distribution, timing, magnitude and forcing of Holocene climatic events. Sedimentary logs, diatom assemblages, stable isotopes and pigments were used as proxies to reconstruct AP ice sheet retreat, fluctuations in sea ice extent, changes in water mass circulation and ice shelf collapse events. This has revealed the spatial and temporal heterogeneity of climate events through the Holocene. The marine environment of the western AP (WAP) experienced deglaciation onset of the Mid Holocene climatic optimum and climatic deterioration into the Late Holocene considerably earlier than the marine environment of the eastern AP (EAP) and AP terrestrial records. These differences suggest that the climate of the WAP has been more closely connected with the SE Pacific, through coupled ocean-atmosphere interactions (such as the position of Southern Westerlies and El Nino Southern Oscillation frequency), whereas the EAP displayed a closer affinity with AP terrestrial records and the cryospheric influences of the Weddell Sea. This investigation has emphasised the complexity of the climate system of the AP on a range of spatial and temporal scales and highlighted that no single record can adequately represent regional palaeoclimate records must be developed from the oceans and continents and then interpreted as an assemblage.