PICCOLO
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Overhead shot of scattered icebergs. Credit: Carson McAfee (BAS)22 February 2024
Yixi Zheng (UEA)
Sometimes I forget how privileged we are to be in this remote place, but those icebergs always remind me of this.
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One by one, those icebergs come to us following their fates. I see their figures shrinking and expanding through our windows. I embrace each with joy, and say farewell to them with a tad feeling of loss. Whether large or small, they do not drift fast with the impulse of waves, but move slowly and quietly near in their own place. If they were to gaze around, I wonder if they would notice a friend who just arrived and is now departing. I know it is very likely the last time I see them, and probably the last time they see a human.
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Icebergs are glacial pieces that have detached from glaciers into the ocean. Where we are, the western Weddell Sea, they are normally calved from the Filchner and Ronne Ice Shelves or Larsen Ice Shelf and they preserve the features of these ice shelves.
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This iceberg contains many blue and white layers. The difference of the colour is a result of the changing seasons. When snow accumulates on the top of a glacier, it builds a white layer of very fluffy snow. This layer of snow will then be separated into two layers. The lower layer is compressed by the gravity and forms a layer of bubble-rich ice, therefore becoming white because the bubbles reflect a broad spectrum of light. Another layer melts in summer and releases the bubbles before it refreezes in winter, so it becomes blue due to the lack of bubbles. Every year, a blue layer of relatively solid ice and a white layer of relatively loose ice are formed. The layers of this iceberg are very clearly shown here as the snow covering it has been washed off by seawater.
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Prof Karen Heywood (UEA)
Icebergs come in all shapes and sizes. Sometimes they have flat tops and steep cliffs on the sides. These icebergs have seen better days – they’ve probably come a long way from their parent ice shelves, and encountered rough weather and bumped into other icebergs, hence their craggy appearance. The flat area of ice in the front of this photo isn’t from icebergs, it is frozen seawater and is much flatter and thinner, maybe a metre or so thick. The seals and penguins ride along on the sea ice.