Tag Archives: Arctic

Ice bores and what they can tell us

Map of Greenland sheet showing depth of iceAbout forty years ago, I was lucky enough to be involved in organising a scientific expedition to North-East Greenland.  Our basecamp was on the Bersaerkerbrae Glacier in Scoresby Land, which at 72 degrees North is well within the Arctic Circle and forty years ago was only accessible in summer when the snow receded.  We measured ablation rates on the glacier [1], counted muskoxen in the surrounding landscape [2] [see ‘Reasons for publishing scientific papers‘ on April 21st 2021] and drilled boreholes in the ice of the glacier.  We performed mechanical tests on the ice cores obtained from different depths in the glacier and in various locations in order to assess the spatial distribution of the material properties of the ice in the glacier. This is important information for producing accurate simulations of the flow of the glacier, although our research did not extend to modelling the glacier.  We could also have used our ice cores to investigate the climatic history of the region.  The Greenland ice sheet contains an archive record of the climate on Earth for about the last half million years, stored in the snow and trapped air bubbles accumulated over that time period.  If the ice sheet melts then that unique record will be lost forever.

The thumbnail image is a map of the depth of ice in the Greenland ice sheet.  The map is about five years old and has a wide green fringe along the east coast.  Scoresby Land is the penisula to the north of the large fiord in the middle of the east coast.  In 1982, the edge of the ice sheet was about 80 miles from the Bersaerkerbrae Glacier, whereas today it is at least twice that distance because the ice sheet is receding.

References:

[1] Patterson EA, 1984, A mathematical model for perched block formation. Journal of Glaciology. 30(106):296-301.

[2] Patterson EA, 1984, ‘Sightings of Muskoxen in Northern Scoresby Land, Greenland’, Arctic, 37(1): 61-63.

Image: https://upload.wikimedia.org/wikipedia/commons/thumb/b/b5/Greenland_ice_sheet_AMSL_thickness_map-en.svg/2000px-Greenland_ice_sheet_AMSL_thickness_map-en.svg.png

No snow at Christmas?

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Norwegian Arctic (Image by Sarah)

The algae in the Arctic Ocean are blooming earlier every year at the moment because the sea ice melts more quickly each Spring as a consequence of global warming. This observation was made by Kevin Arrigo, a biological oceanographer at Stanford University and confirmed by Mati Kahru, an oceanographer at the University of California, San Diego using satellite imaging. But what’s good for algae is not good for polar bears or us because less ice deprives polar bears of a hunting platform and raises sea levels globally. A 1m rise in sea level would displace 145 million people, or the equivalent of about half the population of the USA. A 2 degree temperature rise would make the Earth as warm as 3 million years ago when sea levels were between 25m and 35m higher – the temperature in the Arctic in last month was 2.22°C above average for the time of year.  The extent of the sea ice in October was 28.5% less than average for the month. So while there will be snow at Christmas in the Arctic, there might not be in the future.

Our current engineering technology is both contributing to climate change and is inadequate to mitigate the consequences. These issues present a series of great opportunities disguised as insoluble problems (quoting John Gardiner), and given the predictions of the UN Intergovernmental Panel, we have less than 40 years to replace the equivalent of 200 years of engineering development (paraphrasing Yoshiyuki Sakaki). So, the generation of students entering engineering at the moment are going to be engaged in race that’s more challenging and more important to society than the race to the moon that preoccupied the generation that preceded mine.

Sources

Carl Zimmer, Global warming altering the Arctic food chain, Taipei Times, November 27th, 2016.

Blockstein DE, Weigman L, The Climate Solutions Consensus. Island Press, Washington, 2010.

John Gardiner, founder of Common Cause cited in Friedman, Thomas L., Hot, Flat and CrowdedWhy we need a green revolution and how it can renew America, Farrar, Straus & Giroux, New York, 2008.

Yoshiyuki Sakaki, President, Toyohashi University of Technology, Japan, Keynote presentation at ICEE/ICEER conference in Seoul, Korea, 25th August 2009.