Introduction
Does Lake Superior completely freeze over? It’s a question many people living around and visiting the Great Lakes area often ask themselves. Lake Superior is by far the largest of the Great Lakes, containing around 10 percent of all of the world’s fresh water. Because of its immense size and its proximity to the North Pole, many expect Lake Superior to be the first of the Great Lakes to freeze over in the winter. However, while the lake has partially frozen in the past, it usually only partially freezes, leaving some areas open all year long. So, what factors have caused it to remain partially frozen, and what implications does this have for the local environment?
Physical Factors
The physical characteristics of Lake Superior make it one of the most difficult of the Great Lakes to completely freeze over. At 868 feet (264 meters) deep and containing 3,332 cubic miles (13,680 cubic kilometers) of water, the sheer volume and depth of Lake Superior make it difficult for cold air to reach the entire lake. In addition, the lake is fed by numerous tributaries from all across the Great Lakes basin, and because these tributaries are typically warmer than the lake itself, this further reduces the chance of Lake Superior completely freezing over.
Effects of Lake Effect Weather
Another factor that affects the freezing of Lake Superior is the lake effect weather associated with the lake. When cold temperatures combine with the moisture from Lake Superior, they create large snowstorms. These snowstorms are often localised, and the snow they bring tends to insulate the lake, again reducing the chances of Lake Superior completely freezing over.
Interesting Facts
Despite the fact that Lake Superior usually only partially freezes, there have been times in the past when it has been entirely frozen over. In 1820 and 1821, the lake was so cold that the entire lake froze over. This resulted in people being able to cross the lake on foot, and frozen lake effect snowstorms closed roads and byways.
Environmental Effects
As mentioned earlier, Lake Superior does not completely freeze over, even in the winter months. This has a variety of environmental effects, both positive and negative. Firstly, it means that Lake Superior does not seem to act as an insulator for the surrounding area. This, in turn, means that the air temperatures surrounding the lake remain milder than they would otherwise be. On the other hand, the fact that Lake Superior does not completely freeze over also means that there is a large amount of organic matter that can end up in the lake.
Implications for Local Communities
In addition to its environmental effects, the fact that Lake Superior does not completely freeze over has a variety of implications for local communities. One of the most obvious is that it can make navigation across the lake difficult, as the surface of the lake is not completely frozen. Furthermore, the fact that the lake does not completely freeze over means that it is difficult to harvest ice from the lake, as it is not safe to traverse the frozen portions.
Research by Scientists
The fact that Lake Superior does not completely freeze over has been explored by numerous scientists. They have found that, even though the lake often remains partially frozen, the amount of freeze cover tends to vary greatly from year to year. Furthermore, they have identified that the rate of freeze cover is decreasing over time. This has led some experts to suggest that rising global temperatures are restricting the amount of time that Lake Superior is able to remain frozen.
Protection of Local Species
Finally, the fact that Lake Superior does not completely freeze over has implications for the protection of local wildlife and species. As the lake does not completely freeze over, it provides a safe haven for various species to over-winter. These species include fish, birds, and other aquatic life, which can remain in the lake without having to worry about being frozen out.
Conclusion
In conclusion, it is clear that Lake Superior does not completely freeze over, despite its immense size and proximity to the North Pole. This is due to a combination of physical characteristics, lake effect snowstorms, historical occurrences and environmental factors. Furthermore, the lack of complete freeze cover has implications for both the environment and local communities, as well as local species. As such, it is important to consider the impacts of climate change and global warming on Lake Superior and its freeze cover.
