Holocene tephrostratigraphy in high-latitude peatlands of the Southern Hemisphere: a link through time?

Wednesday, 17 December 2014
Thomas P Roland1, Matthew John Amesbury2, Dan Charman3, Francois De Vleeeschouwer4, Dominic Hodgson5, Paul Hughes6, Dmitri Mauquoy7, Natalia Piotrowska8, Jessica Royles9, Simon van Bellen7 and Heleen Vanneste10, (1)University of Southampton, UK, Southampton, United Kingdom, (2)University of Exeter, Exeter, United Kingdom, (3)University of Exeter, Exeter, EX4, United Kingdom, (4)EcoLab France, Castanet Tolosan, France, (5)NERC British Antarctic Survey, Cambridge, United Kingdom, (6)University of Southampton, Southampton, United Kingdom, (7)University of Aberdeen, Aberdeen, United Kingdom, (8)Silesian University of Technology, Gliwice, Poland, (9)University of Cambridge, Cambridge, United Kingdom, (10)EcoLab France, Castanet-Tolosan, France
We present preliminary tephrostratigraphic data from south Patagonian peatlands and moss banks from the Antarctic Peninsula that provide greater chronological constraint to Holocene palaeoclimatic records and increase the potential for inter-regional correlation.

Relative to the Northern Hemisphere, there is a paucity of high-resolution, robustly dated Holocene palaeoclimate records in the Southern Hemisphere, limiting our ability to validate climate models in this region and fully understand variation in the global climate system over time. In the absence of long-term instrumental data, multi-proxy (testate amoebae, plant macrofossils, δ13C, δ18O and δD) palaeoclimatic records from south Patagonian peatlands can provide valuable information about the long-term variability of the southern westerlies, a key component in determining the Southern Ocean’s function as a sink or source of atmospheric carbon dioxide. Similarly, multi-proxy palaeoclimatic reconstructions from moss banks provide a unique terrestrial palaeoenvironmental archive from the Antarctic Peninsula, where records of past ecological change are rare and provide vital context for the recent, rapid biotic change recorded since the mid-20th century.

Robust chronologies are imperative for the accurate examination of spatial and temporal patterns in Holocene climate variation. Previous work has confirmed the presence of discrete tephra horizons in south Patagonian peatlands and Antarctic Peninsula moss banks but the examination of distal, cryptotephras is currently underemployed as a geochronological tool. The chronological potential of these archives is considerable, given their high and largely continuous accumulation rates and suitability for 14C dating, presenting additional opportunities to refine the ages of major Holocene eruptions. Here, we present initial tephrostratigraphic results from both regions and explore the links between them.