Abstract
Abstract. Old ice for paleo-environmental studies, traditionally accessed through deep core drilling on domes and ridges on the large ice sheets, can also be retrieved at the surface from ice sheet margins and blue ice areas. The practically unlimited amount of ice available at these sites satisfies a need in the community for studies of trace components requiring large sample volumes. For margin sites to be useful as ancient ice archives, the ice stratigraphy needs to be understood and age models need to be established. We present measurements of trapped gases in ice from Taylor Glacier, Antarctica, to date the ice and assess the completeness of the stratigraphic section. Using δ18O of O2 and methane concentrations, we unambiguously identify ice from the last glacial cycle, covering every climate interval from the early Holocene to the penultimate interglacial. A high-resolution transect reveals the last deglaciation and the Last Glacial Maximum (LGM) in detail. We observe large-scale deformation in the form of folding, but individual stratigraphic layers do not appear to have undergone irregular thinning. Rather, it appears that the entire LGM–deglaciation sequence has been transported from the interior of the ice sheet to the surface of Taylor Glacier relatively undisturbed. We present an age model that builds the foundation for gas studies on Taylor Glacier. A comparison with the Taylor Dome ice core confirms that the section we studied on Taylor Glacier is better suited for paleo-climate reconstructions of the LGM due to higher accumulation rates.
Highlights
Ice cores from Greenland and Antarctica have provided highresolution climate information over the past eight glacial cycles (EPICA Community Members, 2004)
Blue ice areas, where ancient ice is brought to the surface by ice flow, and especially continental ice margins have been recognized as valuable, inexpensive archives of paleo-climate information, which are not encumbered by sample size restrictions (Sinisalo and Moore, 2010; Petrenko, 2013)
Taylor Glacier is the first ice margin site in Antarctica where paleo-atmospheric gas records from the last glacial cycle have been explored in detail
Summary
Ice cores from Greenland and Antarctica have provided highresolution climate information over the past eight glacial cycles (EPICA Community Members, 2004). The combination of value-matching δ18Oatm and feature-matching sharp methane transitions allows us to unambiguously date ice from most time intervals, making it a powerful dating tool This method has been used previously to synchronize the timescales of deep ice cores (Chappellaz et al, 1997; Capron et al, 2010) and was successfully used at the Pakitsoq ice margin in West Greenland to date a sequence of layers covering the last deglaciation (Petrenko et al, 2006; Schaefer et al, 2009). The aim is to date the ice and study the deformation it has acquired on its travel path, to assess archive integrity At this site virtually unlimited amounts of old ice can be collected at the surface, allowing for the application of new proxies that have hitherto been precluded by sample size restrictions (Buizert et al, 2014; Petrenko et al, 2016), and increasing the precision of established measurements that are hindered by small sample volumes. We present a high-resolution age model for 8 to 55 ka BP and highlight the differences of Taylor Glacier and the Taylor Dome ice core in the characteristics of their firn columns during the deglaciation and the Last Glacial Maximum (LGM)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
