I’m exploring the story of ice and icebergs, part 1 of this mission can be read here!
Disclaimer: I’m not a scientist. As for credentials, I’ve got a lot of books about ice at the office and in Grade 4, I got a 100 in science on my report card.
So an iceberg is just a chunk of… floating ice… right? Simply, yes! But what does that even mean? Icebergs are not sea or pack ice, icebergs are pieces of glaciers that have calved.
What are glaciers? And what is calving?
Glaciers are packed snow. Antarctica and Greenland are the only places where frigid temperatures keep the snow from never fully melting. Antartica in the south (the opposite pole with penguins and no polar bears) is basically one giant ice shelf.
The accumulation builds over time (as old as 10,000 years old), which results in massive parts of the land covered with ice shelves. Glaciers become so heavy, heavy enough that the air bubbles are pressed out of them and then you can see the blue colour in the ice. The glaciers are also so heavy that they also move downward. Gravity pulls them toward the sea.
The word “iceberg” is a loan translation from the Dutch word ijsberg. I’m trying to learn Dutch and I know that ijsberg is the combination of words ice and mountain.
(of cows and certain other large animals) give birth to a calf.“Galloway cows have wide pelvises and calve easily”
(of an iceberg or glacier) split and shed (a smaller mass of ice).“glaciers were calving icebergs directly into the sea”
What makes Ilulissat so special is the continuous process of calving that you can see and hear. Some 35 billion tonnes of icebergs move from land to sea. Part of what makes icebergs beautiful to watch is the way they stay afloat. Icebergs float for several reasons (a) water is incredible and it’s slightly denser as a liquid than as a solid, (b) icebergs have lots of air (!) billion of tiny air bubbles, and (c) dissolved salts in the ocean buoyancy.
Interestingly, and maybe something that we don’t think about is that the ice is not moving by the wind but by currents.
Icebergs also support food chains! When icebergs calve, they bring with them iron rich nutrients. As they melt, they release the nutrients. This supports a whole food chain that develops around the iceberg. Icebergs also aid in carbon sequestration. The icebergs carry with them trapped carbon. When these tiny algae that eat them and die, they fall to the bottom of the ocean (carrying with them the carbon).
Climate scientists study icebergs as they break up for clues to the processes that cause ice shelf collapse. Oceanographers follow icebergs because the freshwater they contribute to the sea influences ocean currents. And biologists study icebergs to find out how they impact ocean life. I, the social science researcher, seek to study icebergs because there is also a deep human connection with the ice. Inuit livelihoods (past, present, and future) rely on the conditions of the ice.
Stay tuned for the different types of icebergs in the next post! Whoever was in charge of classifying them, clearly had a good sense of humour to name small icebergs “Bergy Bit”.