Why glacial lakes are green

Coarse-bubbly ice looks whiter than most other ice because it is filled with small bubbles. This kind is usually found near ablation areas of a glacier. Coarse-clear ice is free of bubbles and is the bluest ice of all.

This kind is usually found near the margins and terminus of a glacier. Look at ice cubes formed in your freezer. These ice cubes first froze on their outsides and trapped air bubbles toward the center. As a result, the exterior is bubble-free while the interior has bubbles. Bubbles between the outside and the inside of the cube are probably longer and more extended. Can you see the differences?

Distributed Active Archive Center. Facebook Twitter. Just Imagine… What would happen if you broke off a big chunk of ice from a glacier and put it in your glass of water? If your chunk of glacial ice melted in your glass of water, you would have dirt, gravel, and even organic matter living stuff in your water. All those pressurized air bubbles would rush out so fast that they might explode your glass!

Glacial ice is a different color than regular ice. It is so blue because the dense ice of the glacier absorbs every other color of the spectrum except blue, so blue is what we see. Photo by Hambrey. Why is Glacier Ice Blue? Glacial ice is different than regular ice. The silt is so fine it does not settle to the bottom quickly, remaining in suspension in the lake water. When light hits the surface of the lake, the silt absorbs some of the light the very short wave lengths like purple and indigo and the water absorbs the longer wavelengths like red, orange and yellow.

Glacial flour is the very fine particles of clay produced by glacial erosion. As the glacier flows down the valley, the ice, which contains many rock fragments, grinds over the valley floor and erodes the rock producing the fine sediment. The intensity of the blue colour can vary depending on the amount of water input where it comes from. The lake is not just fed from glacial streams but from other streams around the catchment.

Further up the valley in Aoraki Mount Cook National Park is the Tasman Glacier lake where the water is quite grey, because of a very high concentration of silt particles. Here the glacier flows directly into the lake, so the water is dominated by glacial melt water.

Our glaciers are shrinking because of human-induced climate warming. Choose low-carbon transport options where possible and take all your waste with you.

Better yet, work to minimise your waste — do your best to look after our Earth. When you are visiting Lake Pukaki and cast your eyes up the sides of the hills. The minerals form the sediments at the bottom of the lake. Numerous glacial lakes appear bright turquoise as if someone is continuously pouring food coloring agents into them. Sometimes, the lakes are so luminescent as if they are under-lit.

Some people actually believe that every year the lakes are emptied then the bottom painted blue while others believe that a dye is often poured into the lake. However, some glacier lakes are naturally blue or turquoise. The blue color seen on most glacial lakes result from the lake formation process. Glacial lakes are formed through the process of glacial erosion.

As the glacier moves on the ground, it erodes the land beneath. The continuous erosion leads to the formation of spaces or large holes. The melting water from the glacier slowly fill the holes or spaces that had been formed by the moving glacier to form a lake. As the glacier moves, it also pulverizes the minerals on the rock over which it moves.