Reconstructing the former geometry and behaviour of glaciers and ice caps is important to understand how contemporary ice masses will respond to ongoing climate change . The West Highland Icefield (WHI) of Scotland existed ca. 13.0–11.5 ka BP and was a transfluent ice-cap complex similar in size to present-day Vatnajökull in Iceland, or the ice-covered portion of Svalbard. It is generally assumed that the advance–retreat behaviour of the WHI was driven by climate change, and that its maximal extent was largely synchronous as a function of enhanced climate cooling during the Younger Dryas Stadial [2,3]. Recently, however, this notion has been challenged, with the possible identification of surge-type glaciers draining the Younger Dryas WHI . From a palaeoclimatic perspective, it is vital to know whether glacier-front fluctuations resulted from (external) climate forcing or (internal) dynamic instabilities, such as surging. This PhD doctoral training project will address this question by examining the landform and sediment record and establish an advance-retreat chronology for several, unusually large, former outlet glaciers in Central Scotland thought to have surged during the Younger Dryas Stadial. Comparing this with evidence from present-day surging glaciers, and other glacier margins known not to have surged, will allow the glacier dynamics of former ice-fields and ice-caps to be better understood and, crucially, will also develop a toolkit for identifying surge-type glaciers in the wider palaeo-record.
This project will focus on the large but little-studied outlet glaciers of the former Scottish WHI draining the Gare Loch, Teith and Forth catchments as well as the well-dated Lomond Glacier [6,7]. These low-gradient glaciers were the largest outlets of the whole WHI and transferred large volumes of ice from the Highlands of Stirlingshire and Argyll to the Lowlands of central Scotland. Two of these glaciers also terminated in water bodies. Much like the largest lobes of Vatnajökull and Svalbard’s ice caps, we predict that these outlets were instability-driven surge-type glaciers . Importantly, if Scottish glacier fluctuations are found not to be climatically driven, their former extent and behaviour should not be used in climatic reconstructions – yet the Lomond, Forth and Teith glaciers all currently constitute type-sites for the timing and palaeoenviroment of the Younger Dryas Stadial in Scotland [3,6-8].
The key aims of this PhD research project will be to:
• Map and characterise the different sediment-landform assemblages associated with these adjacent former glaciers.
• Determine a suite of diagnostic features relating to climatically driven or dynamically driven (surging) glacier fluctuations in Scotland, for use by Quaternary scientists.
• Establish a relative chronology of events using established geomorphological relationships and field techniques.
• Test this chronology using cosmogenic-nuclide exposure age dating and statistical modelling, supported by radiocarbon dating where possible.
• Explore the reasons for matches / mismatches between the advance-retreat chronologies at adjacent WHI outlet glaciers (Gare Loch, Lomond, Forth, Teith).
The successful student will be encouraged to present at conferences and publish journal articles at well-defined stages of their research. The outcomes of this research will feed into numerical ice-sheet models and international databases – part of wider projects to understand the glacial history of NW Europe.