King George Island, located west of the Antarctic Peninsula, experiences regional temperature increase well above the mean global warming trend. In this study we present insight into sedimentary processes during warm and cold phases of the past two millennia to compare these to the recent conditions. The investigation is based on a 928 cm long gravity core plus boxcore from Maxwell Bay between Potter and Marian coves. It covers the past c. 1700 years BP. Sedimentation at the core site is largely controlled by sediments from tributary fjords that discharge into Maxwell Bay. The results show two clear-cut granulometric classes of sediments: Class 1 is finer with the principal mode at 16 µm; this class dominates the Medieval Warm Period. Class 2 is coarser with the principal mode at 36 µm; it dominates the Little Ice Age (LIA). Further analyses show that Class 1 sediments are likely a composite of Class 2-type sediments plus a possibly unimodal sediment with the principal mode around 16 µm (hence Class 1). This sediment has likely been transported in suspension as a result of increased meltwater production. As expected, colder climate phases were less affected by melting processes than the warmer ones. However, after the LIA sediments become finer but largely lack the meltwater signal. Until AD 2000 no shift from Class 2 to Class 1 sediments is visible which indicates that at least in terms of the associated sedimentary processes the present warming trend is different to those of the recent past.
Helmholtz Research Programs > PACES I (2009-2013) > TOPIC 2: Coastal Change > WP 2.3: Coastal Systems under Global and Regional Pressures