Geochemical characterization of Maxwell Bay sediments evidences for late Holocene climate variability at King George Island, maritime Antarctica

• Main Authors: Monien, P., Schnetger, B., Hass, H. C., Kuhn, Gerhard, Brumsack, H.-J.
• Format: Conference Object
• Language: unknown
• Published: 2010
• Subjects: Antarctic; Antarctic Peninsula; Barton; Barton Peninsula; King George Island; Maxwell Bay; Antarc*; Antarctica
• Online Access: https://epic.awi.de/id/eprint/23717/; https://hdl.handle.net/10013/epic.36634

Since the middle of the 20th century the Western Antarctic Peninsula (WAP) belongs to the regions with the most rapid warming on Earth and thus to one of the hotspots of climate change. During the last six decades a mean temperature increase of 0.9 to 2.5 °C is observed along the WAP (Turner et al. 2005, Steig et al. 2009). Concomitantly, a dramatic retreat of glaciers is reported that has even accelerated in the last decade (Rignot et al., 2008). These changes are regionally accompanied by enhanced meltwater discharge transporting huge loads of eroded material into coastal waters. During R/V Polarstern cruise ANT-XXIII/4 in 2006, a gravity core (PS 69/335-2) and a giant box core (PS 69/335-1) were retrieved from Maxwell Bay, King George Island. Geochemical analyses (quantitative XRF, ICP-MS) and radiodating (14C, 210Pb) were performed on both cores. A comparison with geochemical data of local bedrocks evidence the predominantly detrital origin of the sediments, most likely derived from Barton Peninsula. Variations in the vertical distribution of selected elements indicate alternating supply areas due to changing glacier extensions during the past 1,750 years that may be linked to main Neoglacial events, equivalent in timing with the Little Ice Age (600 - 100 yrs BP) and the Medieval Warm Period (1,250 - 600 yrs BP). 210Pb excess data further revealed that mass accumulation rates have almost tripled since 1940 (0.64 g cm-2 yr-1 in 2006). This is presumably related to the glacier retreat due to the recent rapid regional warming.