Scotland’s ‘400-year-old’ glacier

Martin Kirkbride after sampling one of the boulders in Coire an Lochain
Satellite image of the Oraefajökull ice cap, from which Virkisjökull drains towards the west.

A study involving Dr Jez Everest of BGS Scotland and the University of Dundee, has found evidence that suggests Scotland may have been home to a small glacier within the last 400 years — some 11 000 years less than previously thought.

It had long been understood that Britain's last glaciers melted around 11 500 years ago.

However, the combined BGS and Dundee University team has now established that a glacier was in place in the Cairngorms possibly as recently as the 18th century.

Little Ice Age glacier

Using a technique called cosmogenic 10Be dating, the research team have shown that a small glacier in Coire an Lochain in the Cairngorms piled up granite boulders to form moraine ridges, possibly as recently as the last few centuries, during the period of cool climate known as the Little Ice Age.

The dating indicates that the moraines were formed within the last couple of thousand years, which shows that a Scottish glacier existed more recently than was previously thought.

The climate of the last few millennia was at its most severe between 1650 and 1790, and there are some anecdotal reports from that time of snow covering some of the mountain tops year-round.

We now have strong scientific evidence that there was indeed a glacier. Scientists had speculated that glaciers may have re-formed in the Highlands around the time of this Little Ice Age, but hard evidence has proved to be elusive.

Cosmic rays ‘date rocks’

This long term research project began with sampling of the morainic boulders was carried out in 2007 and 2011. In 2012, Dr Martin Kirkbride (University of Dundee) and Dr Jez Everest (BGS) teamed up with the Cosmogenic Isotope Analysis Facility at the Scottish Universities Environmental Reactor Centre in East Kilbride, to carry out the laboratory analysis.

The dating technique estimates the time since quartz crystals in granite boulders were exposed at the Earth’s surface, based on measuring the concentration of beryllium-10 isotopes, which form when the rock surface is bombarded by cosmic rays from deep space.

The discovery of the glacier is backed up by a parallel study by Dr Stephan Harrison (University of Exeter) and Dr Ann Rowan1 (University of Aberystwyth). They have developed a numerical climate model to simulate Little Ice Age climate in the Cairngorms, allowing them to calculate how much cooler and snowier the winter weather must have been to cause glaciers to form.

The models show that small glaciers would have been created in the corries by a cooling of air temperatures by 1.5°C and precipitation increasing by ten per cent. However present climate warming means there is little chance of a return of glacier ice to the Highlands for the foreseeable future.

Research papers

Kirkbride, M, Everest, J, Benn,D, Gheorghiu, D and Dawson, A.  2014. Late-Holocene and Younger Dryas glaciers in the northern Cairngorm Mountains, Scotland. The Holocene, February 2014 vol. 24 no. 2 141-148.

Harrison, S, Rowan, A V, Glasser, N F, Knight, J, Plummer, M A, and Mills, S C.  2014.  Little Ice Age glaciers in Britain: Glacier–climate modelling in the Cairngorm mountains.  The Holocene, February 2014 vol. 24 no. 2 135–140.

 

'A corrie, yesterday' in true newspaper speak.

Comment and debate

There has been considerable interest in the recent publication these two papers published in The Holocene, which each, in very different ways, present evidence that a glacier or glaciers formed in the Cairngorm Mountains during in the ’Little Ice Age’.

These papers have attracted criticism from Dr Adam Watson, a highly-respected retired scientist, author campaigner, and commentator on Cairngorm affairs, and someone who we have always held in high regard.

It is of course, anybody’s right to criticise scientific ideas, we have no issue with the fact that our work is open to criticism and debate.

However, our professional competence and credibility is being called into question without these criticisms being subject to peer review.

A full statement, posted on the University of Dundee’s website, is our final response to Dr Watson’s latest comments, but we are not using it to add to the debate.

Enough has been said, and it’s for others to form their own views based on the evidence and arguments already presented from both sides. We have requested that our critic be asked to submit his comments to the journal The Holocene in which the work was published, and to which we would have a right to reply.

Both would be peer-reviewed by fellow scientists. Clearly there is plenty of scope for more research to be done.

Contact

Contact Jez Everest (BGS) or Dr Martin Kirkbride (University of Dundee) for further information