Scientists get clues on climate change by looking back to Ireland’s Ice Age

National Seabed Survey provides “invaluable” data

Dr Robert Meehan, a consultant geologist and expert on the impact of the ice on Ireland’s topography, says the research that has been gathered is invaluable to understand the climate change that triggers ice ages.

Ireland was literally formed by glaciers as successive ice ages sent wave after wave of glaciers that scored and scoured the surface, leaving behind drumlins and the Burren, not to mention trillions of tons of gravelly waste.

With the current “interglacial” or warm period already having lasted around 10,000 years, the next ice age could be ‘just around the corner,’ to which Dr. Meehan said “This is where the arguments about climate change become interesting.”

Some people argue that the climate change the Earth is experiencing today is part of its natural cycle, while others argue that it is a result of human activity.

Dr. Meehan, who has been studying Ice ages for twenty five ages, has compiled comprehensive maps of glacial sediment left behind in Ireland. Currently, he’s working the first digital glacial sediment and landform maps for the Geological Survey of Ireland.

During the peak of the last ice age, approximately 29,000 years ago, Ireland would have appeared multiple its size as it was laying under up to a kilometer of ice.

Meehan’s studies have shown that only 107sq km of Ireland’s 85,000sq km land mass remained above the ice sheet that blanketed the country. The island and all points north “were completely smothered”, he says.

The eventual movement of the ice sheet helped shape and carve Ireland’s present landscape.
“Once the depth of ice reaches 50m it starts to flow. All of the ice was flowing, it was scouring the landscape.” Dr. Meehan added that the results of the ice flow are visible today in places such as Glendalough in Co Wicklow.

Similarly, peat bogs are where glacial lakes were such a long time ago.

Some wonder why more of Ireland isn’t like the Burren, raw rock that is the result of the scouring movement of the ice. Dr. Meehan explained that only 10 per cent of Ireland is rock outcrop, while “the rest is buried by deep glacial sediments.”

And buried it is, indeed. The present day Curragh in Co Kildare sits atop 110m of sediment, gravel and sand before reaching bedrock. Some of the deepest sedimentary deposits up to 125m thick overlay Offaly, Laois and south Kildare, he says. “There are trillions of tons of sediment.”

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Nster.com