Climate fluctuations during the past two millennia as recorded in sediments from Maxwell Bay, South Shetland Islands, West Antarctica

Abstract

The climate evolution of the South Shetland Islands during the last c. 2000 years is inferred from the multiproxy analyses of a long (928 cm) sediment core retrieved from Maxwell Bay off King George Island. The vertical sediment flux at the core location is controlled by summer melting processes that cause sediment-laden meltwater plumes to form. These leave a characteristic signature in the sediments of NE Maxwell Bay. We use this signature to distinguish summer and winter-dominated periods. During the Medieval Warm Period, sediments are generally finer which indicates summer-type conditions. In contrast, during the Little Ice Age (LIA) sediments are generally coarser and are indicative of winter-dominated conditions. Comparison with Northern and Southern Hemisphere, Antarctic, and global temperature reconstructions reveals that the mean grain-size curve from Maxwell Bay closely resembles the curve of the global temperature reconstruction. We show that the medieval warming occurred earlier in the Southern than in the Northern Hemisphere, which might indicate that the warming was driven by processes occurring in the south. The beginning of the LIA appears to be almost synchronous in both hemispheres. The warming after the LIA closely resembles the Northern Hemisphere record which might indicate this phase of cooling was driven by processes occurring in the north. Although the recent rapid regional warming is clearly visible, the Maxwell Bay record does not show the dominance of summer-type sediments until the 1970s. Continued warming in this area will likely affect the marine ecosystem through meltwater induced turbidity of the surface waters as well as an extension of the vegetation period due to the predicted decrease of sea ice in this area.

Observed glacial changes on the King George Island ice cap, Antarctica, in the last decade

“…by changes in light climate and requirements for adaptation to increasing sedimentation rates (Schloss et al, 1999;Pakhamov et al, 2003). These higher sedimentation rates might be linked to increased glacier ablation (Hass et al, 2009). On King George Island (KGI) in the SSI environment interdisciplinary research programs are investigating the impact of glacier retreat on marine ecosystems.…”

The Little Ice Age: evidence from a sediment record in Gullmar Fjord, Swedish west coast

“…The period 1675-1710 AD has been identified as the coldest phase (climax) of the LIA (Lamb, 1983), which was preceded by an abrupt and rather short-lived warming around 1600 AD, according to some studies Hass et al, 2010). The Little Ice Age has been generally regarded as a stormy period (Lamb, 1983;de Jong et al, 2007de Jong et al, , 2009.…”

Seafloor geomorphology of western Antarctic Peninsula bays: a signature of ice flow behaviour

“…2), no sedimentological evidence was found of LIA advance (Milliken et al, 2009), which may indicate that if there was any LIA advance in the western AP bays, only smaller systems (narrow bays) and/or shallow bays would record and preserve any geomorphic evidence, as suggested by our observations above. The LIA event has been reported in western AP bays and the South Shetland Island by several authors (Domack et al, , 2001Shevenell et al, 1996;Hall, 2007;Hass et al, 2010;Monien et al, 2011;Simms et al, 2012) but it may be a more widespread event throughout the AP than previously assumed. However, it is worth noting that LIA interpretations by those authors were based on sedimentological or terrestrial analysis that included results from dating techniques.…”