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12 Days till Christmas – Day 8. Carving of Ice

12 days till Christmas - reflections from a leadership journey for Women and non-binary in STEM focusing on sustainability, climate change and global challenges- culminating in an expedition and leadership journey to Antarctica. 


Icebergs in the Gerlache Strait: L-R: small icebergs litter the channel, a large cruise ship navigates the floating ice, the sunsets on icebergs in the Gerlache. November 21st, 2023.

The term ice carving has a somewhat pleasing feel to me. Images of beautiful blue glacial ice shedding from the toe of a glacier into aquamarine waters. But now the images of chunks of ice falling into blue seas are synonymous with climate change and the rapid loss of mountain glaciers and polar ice. Although icebergs are a natural phenomenon the acceleration of glacial retreat in the mountains and the carving of major ice sheets from Antarctic ice shelves is alarming.

 

Whilst we were at sea the iceberg A23a was travelling northwards out of the Weddell Sea, 38 years after carving from the Filchner Ice Shelf and then being grounded and stuck on sea floor muds it is travelling north and escaping the clutches of Antarctica. It is almost 4,000 sq. km more than twice the size of Greater London and weighs a trillion tonnes. The ship we are on is 120m long and the thought of meeting this colossus moving iceberg in quite daunting. Having been released from its muddy parking spot in the summer of 2020 it has slowly been moving northwards. As I write this, a few days before Christmas, it has rounded the end of the Antarctic Peninsula and is about to enter the open Ocean and be at the mercy of the Ocean currents and winds that will likely drive it up ‘iceberg alley’ towards South Georgia.


Icebergs and iceberg A23a. Top L-R: The location of iceberg A23a on November 15th 2023. The white dots show historic iceberg paths - the track north eastwards to South Georgia is know as 'Iceberg Alley' (source: Polar view and the BBC), a tabular iceberg - evidence of carving from an ice shelf, satellite image of iceberg A23a showing it's massive size in relation to surrounding islands (source: Copernicus Sentinel-3 and the BBC). Bottom L-R: a large tabular iceberg, ocean currents driven by deep water formation in Antartica and the cold circum Antarctic current (source: AntarticaGlaciers.org), icebergs near our ship.

There are tabular iceberg’s everywhere evidence of the break-up of the ice shelves, the ship’s crew say there are many more than normal and much further North. We spend a truly majestic evening in the Gerlache Strait. The intensity of pinks, yellows, purples, and blues are hard to comprehend, there is also a mirror like stillness and so much ice. The captain is radioed by a nearby ice breaker inquiring whether there is a way through. We make it despite the intensity of ice. Later we have a close call in the Antarctic Sound as brash and other ice are pushed into the Sound almost blocking our escape. Strange winds are blowing, and ice is all around.

 

The icebergs are stunningly beautiful, but they are an ever-present reminder of the changes that are taking place at our planet’s poles and in our mountains: loss of ice. The cryosphere is diminishing and with it changes in sea salinity that affect currents, habitats, biodiversity, and the planet’s ability to absorb and reflect heat. The Southern Ocean and Antarctica may seem a long way away, but changes here have profound affects elsewhere. The melting of Antarctic ice creates deep ocean bottom waters that drive ocean circulation and currents. With these currents heat/coolth and plankton are transported to other parts of the globe. Changing patterns in ocean circulation affect global weather. With a decrease in the Earths’ ability to reflect and absorb heat the result will be increased global temperatures that further drive warming, creating a feedback loop of more ice loss, global change and not least sea level rise. Changes in Antarctica are and will affect us all.

 

@HomewardBoundprojects

@aberdeenuni

@UoAGeosciences

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