| Summary: | Abstract: As is observable today, Arctic glaciers are especially sensitive to climate change. By studying the past fluctuations in glacier extent, we can determine the cause of these fluctuations due to climatic shifts in temperature, albedo, and green house gas accumulation. Here, we investigate the fluctuations of Linnebreen, a high Arctic glacier located in southwestern Spitsbergen, Svalbard, throughout the Holocene in order to investigate its reaction to the cooling temperatures seen in the Holocene. We use cosmogenic 10Be surface exposure ages of moraine boulders deposited on moraine remnants found just outside of the Little Ice Age (LIA) moraine. We use this same technique on boulders found in Linnedalen beyond the extent of the LIA moraine and upstream of Linnévatnet to investigate when Linnebreen retreated to the LIA extent in the early Holocene. The approximate age for the Neoglacial moraine remnant is 1.6+/- 0.2 ka. The samples taken from glacial erratics in Linnedalen place the retreating glacier outside the LIA moraine at 12.4 +/- 0.4 ka. Rather than seeing a steady advance of this high Arctic glacier after ice-free conditions in the early to middle Holocene that ended in the LIA maximum, we see an early maximum that ended at ~1.6 ka followed by a readvance during the LIA, which may be observed at several other Svalbard glaciers. This late Holocene, pre-LIA ice advance and retreat suggests a more complicated response of Svalbard glaciers to the gradual Arctic cooling of the Holocene and may be related to a centennial-scale reduction in sea ice from northward incursion of Atlantic waters around Svalbard. Such a response would imply that transient warming overwhelmed increased precipitation from reduced sea ice and highlights the sensitivity of Svalbard’s cryosphere to reductions in sea ice.
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