, 4 min, 799 words
Tags: alaska how-stuff-works kayak-adventures
I was pretty unsatisfied with my first take on glaciers 101. Here's another attempt, after letting that stew for a while.
Glaciers are massive bodies of moving ice. Their scale is enormous, so it's easiest to understand them in comparison to more familiar topics.
Glaciers are like rivers. They are fed upstream where lots of snow falls, and they flow downhill via the path of least resistance.
Glacial ice is like a very squished snowball. Over the course of years of snowfall, snow gets compressed to grainy ice like a snow cone. Over the next few years, it gets further compressed into glacial ice, containing less than 20% air, compared to 90-95% air in freshly fallen snow.
Glaciers are like otters. They can be classified by where they live. In the case of glaciers, that means classifying them by where their terminus, or end, is located. If a glacier ends in the mountains, it's an alpine glacier. If it ends in the ocean, it's a tidewater glacier. Aialik is a tidewater glacier. That means it has a slightly different life from alpine glaciers, just like river and sea otters have different lives based on their environments.
Glaciers are like shedding dogs. They are constantly losing ice. They lose some ice to the sun and warmth of summer. Other ice is shed by calving into the ocean. If the glacier loses ice faster than it's being replenished by snowfall up high, it's like the dog losing hair faster than it can regrow. The dog will go bald, and the glacier will retreat. If the dog is growing hair faster than it's being shed, the dog's hair grows thicker. The glacier, in turn, will advance. Retreating and advancing are totally natural for a glacier to do, and they reflect all sorts of conditions around them, from the temperature of the air to the quantity of snowfall to the topography of the bedrock underneath it.
And glacial ice is like liquid water. In small quantities, like an ice cube or a glass of water, it looks clear. In larger quantities, like in a lake or a large block of glacial ice, it starts to look blue. That's what gives the glacier this characteristic deep blue.
Glaciers are like sandpaper. They pick up rocks, both big and small, and then grind them along the landscape as they flow downstream.
Glaciers are also like bulldozers. They can push rocks all the way from the tops of mountains to the middle of plains, even straight into the ocean.
Glaciers are like fertilizer. In grinding up rocks they pass over and then dumping that dust into the sea, they supply the ocean around here with iron. Just like you need iron to function – it's used to carry oxygen in your blood – it's crucial to the existence of phytoplankton, which forms the base of a food chain stretching all the way up to whales.
And tidewater glaciers are like unicorns. They're hard to find but unbelievably precious when you do. This is a very special place, and I'm so excited to share it with you today.
I want to play with the order of those comparisons to make them tell a cohesive story, and I want to leave space for curiosity too! This is very much a work in progress, but I am way happier with it than with my attempt from yesterday.
Today I had the immense pleasure of shadowing my very first Aialik day trip. It was incredible, with three species of whales spotted before ten in the morning. That included two fin whales, the second largest animal living on Earth today, as well as one breaching orca. Other guides joked that this is what it's like every day, because it's so obvious that our trip today was an outlier. But hey, I'm not complaining. Other highlights: