Blowing Hot or Cold? Assessing the terrestrial impact of North Atlantic stadials and abrupt climate change. We're using geomorphic mapping and cutting-edge geochronology to reconstruct ice-sheet behaviour in the British Isles during the last glacial termination, a period characterised by abrupt shifts in mean climate state, such as 'Heinrich stadial 1' (18,200-14,700 years ago) and the 'Younger Dryas' (12,800-11,600 years ago). Such constraint is crucial because of currently conflicting models of how such events impact terrestrial environments (e.g., Europe) and recent thinking attributing this disparity to enhanced seasonality in the North Atlantic basin. This work also seeks to tie the North Atlantic region into global models of abrupt change by employing a similar methodology to that I use in my tropical investigations. In focusing on the Scottish moraine record, we are exploiting the straightforward relationship that exists between climate and glaciers: climate warms, glaciers shrink, and vice versa. And because our field site is located within the North Atlantic Ocean, any significant change in the latter should be represented in the moraine record.
This investigation, which was conceived in the Lamont Hall library one night in 2009, began in earnest in April 2010 with our preliminary coring expedition to Rannoch Moor. The goal of that element was to use the post-glacial sediment record and radiocarbon dating to determine when the moor, which formed the centre of the late-glacial 'West highland Ice Field', became ice free: Was it at the end of the Younger Dryas, as the existing paradigm holds, or significantly earlier? Our findings, which were published in PNAS in 2014, suggest that, paradoxically, the last deglaciation of Scotland took place during full stadial conditions. This was the impetus for our ongoing work, which combines cosmogenic Beryllium-10 and radiocarbon dating to construct high-resolution moraine chronologies and snowline reconstructions for the entire termination in Britain.
Harold Borns (University of Maine)
Tom Lowell (University of Cincinnati)
Joerg Schaefer (Lamont-Doherty Earth Ob.)
Thomas Sandford (University of Maine)
Holly Thomas (University of Maine)
Donald Rice (Dundonnell Estate)
Project supported by National Geographic/WAITT
and University of Maine Faculty Research Fund
Project News and Updates
4 October 2016 - Publication
7 September 2016 - National Geographic/WAITT Fund Award
I'm thrilled to announce that we've received funding from the National Geographic/WAITT Fund to help construct a deglacial transect in NW Scotland. We shall now begin preparing for a sampling excursion in the spring (or what passes for spring in Scotland), along with our colleagues from Cardiff University and IFREMER. Stay tuned as we put this one together..
20-23 March 2016 - Field sampling in NW Scotland
March 2015 - Field sampling in NW Scotland
14 April 2014 - Publication