Glaciers are large bodies of dense ice that have formed and accumulated from a build-up of snow over many years. Glaciers are pretty remarkable creations, not least because they are constantly moving under their own weight. The vast majority of glaciers are found in the most extreme condition of the polar regions – though some can be found in mountain regions like the Alps.
Now, we all know that glaciers are made of ice, right? Indeed, one of the most stunning sights to greet visitors to Antarctica is the stunning blue ice of the glaciers. But, we also know that ice is clear and doesn’t have any color. So, why is it that glacial ice is blue in color? This is a question many have spent years wondering about, and we’re hoping to get to the bottom of it today.
It’s not just frozen water
The understanding we most have of ice is that it is basically frozen water. When we put our ice cubes in the freezer, we fill the tray with water, and we leave them in the freezer until they solidify into cubes of ice. But, this is not how glacial ice works, and it’s important to understand the difference. For one thing, the crystals are larger in mass, and the ice has been compacted over the years, maybe even centuries, so that its structure is entirely alien from what we are used to seeing.
One of the most fascinating (and appealing) things about glacial ice is that it has been around for so long. In fact, much of the glacial ice found in the Antarctic is some of the oldest on the continent. In fact, scientists have carried out studies and determined that this blue ice is thought to be around one million years old. And, that’s not all – scientists believe that some ice is even older than that, and there are still projects underway to find older ice.
Why is it blue?
So why are glaciers blue in color? Well, the most logical reason seems to be that it is much easier for water to absorb other colors in the spectrum. What happens is that the water molecules absorb other colors more efficiently than blue, so blue is what we see. The longer the light must travel in ice, the more blue it appears. The reason ice appear blue and not snow is because light cannot penetrate snow deeply enough to make it appear blue before bouncing the light back to us.
It’s pretty incredible how much of an effect the light spectrum can have, and how the mass and density of glaciers can make them appear to be blue in color. If you are ever lucky enough to see a glacier, you will now understand how it achieves its unique color. These incredible masses of blue ice only account for about one percent of Antarctica, but they are certainly one of the moist majestic and memorable parts of the continent. If you want to see ancient blue ice Antarctica is the place to do it. Other places in the world have glaciers as well, but you might be hard-pressed to find a blue one!