Chironomid-inferred summer temperatures for the Last Glacial–Interglacial Transition from a lake sediment sequence in Muir Park Reservoir, west-central Scotland

• Published in: Journal of Quaternary Science
• Main Authors: Brooks, S.J, Davies, K.L, Mather, K.A, Matthews, I.P, Lowe, J.J
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Wiley 2016
• Subjects: glacier; Greenland; Greenland ice core; ice core
• Online Access: http://researchspace.bathspa.ac.uk/16199/; https://doi.org/10.1002/jqs.2860

Lake sediments spanning the Last Glacial–Interglacial Transition (LGIT: ca. 14.7 to 8 ka BP) from Muir Park Reservoir (MPR) in west-central Scotland were analysed for chironomids. The site lies just outside the southern limit of a former glacier that advanced into the Loch Lomond Basin during the Loch Lomond (Younger Dryas) Stadial. Chironomid-inferred mean July temperatures were derived using a modern Norwegian calibration dataset. Three tephra layers constrain the sequence chronologically. Inferred temperatures decline from a high value early in the Interstadial, punctuated by two cold oscillations, probably equivalent to GI-1d and GI-1b in the Greenland ice-core record, and a warm oscillation (equivalent to GI-1a) immediately before the severe cooling at the start of the Loch Lomond Stadial (GS-1), when summer temperatures fell by about 5 °C below the Interstadial average. Summer temperatures fell by about 3 °C below the Interstadial average during GI-1d, which is less severe than inferred from other chironomid records from eastern Scotland, and may reflect the influence of an oceanic–continental gradient. Cooling during GI-1b was particularly strong at MPR when minimum temperatures were about the same as those reached during GI-1d, unlike other sites investigated where GI-1d is usually between 1 and 2 °C cooler than GI-1b.