On our way to Antarctica, sailing through the Drake passage, it didn’t take long until we spotted our first iceberg. Only the evening before, we were told to participate in a friendly bet about when we’d encounter the first one that would be larger than our ship, the Island Sky (~90 meters long). It was icebergs galore soon after. Everywhere we went, we were surrounded by floating ice of various sizes and shapes, especially in the Gerlache Strait and in Iceberg Alley. In fact, the rather narrow Gerlache Strait was so full of ice that we had to discontinue on our intended route because safe navigation through it had became impossible. But it surely made for the most picturesque sights and landscapes that filled me with awe and wonder. Next time I see a body of water, I’ll likely wonder where all the icebergs are. And the penguins, of course
In order to distinguish icebergs, they are typically referred to by their size, as brash ice (<2 meters in length), growlers (<5 meter) and Bergy bits (5-15 meters), and then small (15-60 meters), medium (60-120 meters), large (120-200 meters), and very large (>200 meters) icebergs. We did see several very large ones — they are huge! According to the Captain, one was 300 meters long, and because we were passing it relatively closely, it appeared like a giant wall beside us. Even using the widest angle on my phone, I could not get it into one single picture.
These are typically tabular icebergs, referring to their flat shapes as a result of breaking off of an even larger ice sheet. Other shapes include blocky, wedged, dome-shaped, pinnacle-shaped and dry dock-shaped icebergs. The countless icebergs we saw all had unique shapes but generally they fit in these overarching categories.
Icebergs are assigned a unique designation and tracked with satellite imagery. This way, it can be studied how they move and where they are going. On the east side of Antartica, massive icebergs mostly drift along the coast line in a clockwise fashion, often for 10 years and longer. In the South, some icebergs move away from the coast and then eventually curl around to move around Antarctica at much larger distances. The Antarctic peninsula in the North-West marks the Western side of the Weddell Sea. Most icebergs are found there. They pass right through the Weddell Sea to the follow the north-easterly current towards South Georgia. This part of Antarctica is the warmest area so it is not surprising that the majority of icebergs is found there.
As the icebergs reach warmer and warmer waters, the frozen freshwater begins to melt. Few, if any, make it to South Georgia. At least the ice, that is. Their water is added to the world’s oceans, at rapid pace. With more and more icebergs breaking off due increased ocean and air temperatures, the saltwater becomes diluted. This, in turn, will make icebergs melt faster and faster, worsening the issue. As a result, there is no way to stop sea level rises — the question is how much is will rise at all the different places around the globe. Predictions vary but the take away message remains the same. We need to keep Antarctica as cold as possible because we really don’t want to find out how bad it could get.