Lake Superior is the world’s largest freshwater lake and as an inland sea, it holds an immense amount of fresh water. But how frozen is it? Because of its sheer size, it has a much lower freezing temperature point than most other lakes and rivers. With average temperatures dipping to -20 degrees Celsius, it is a truly formidable body of water.
This coldness is caused by a combination of the lake’s size, the heat and cold air masses interacting with its shallow shores, and the large surface area of the lake in relation to the deeper parts. At maximum depth, Lake Superior reaches 406 meters; however, the majority of the lake is much shallower than this. As the lake is so big, cooling winds can more easily come into contact with its shallow edges. This causes temperatures to dip below what other smaller lakes and rivers would typically experience.
To measure the ice levels on Lake Superior, the National Oceanic and Atmospheric Administration (NOAA) provides the ‘Great Lakes Ice Coverage Index’ which collates satellite data to document the ice levels across each of the five Great Lakes. According to the most recent data, Lake Superior had an ice coverage of nearly 40% as of February 2021.
Given its massive size, Lake Superior reduces ice coverage during the winter more slowly than smaller lakes in the region. For example, Doc Pernette of the Michigan Department of Natural Resources reported in January 2019 that after a colder than usual winter, most of Michigan’s smaller lakes had frozen over with ice sheets up to two to three inches thick. However, at the same time, Lake Superior only showed modest ice accumulation.
Beyond the observations of NOAA and the DNR, there are personal reports about Lake Superior freezing over. Paul Hansen, a local Lake Superior ice fisherman, records stories of his adventures on the lake. According to him, Lake Superior’s ice sheets never exceed a foot in thickness, which is much thinner than the smaller lakes, and he confirms that the lake never fully freezes over. In a recent blog post, he elaborates on his exploratory trips and the serene beauty when walking on the lake in winter, describing the feeling of being a “tiny speck in the vast Great Lakes region”.
Overall, Lake Superior demonstrates the power and complexity of the natural world. It never fully freezes over, and it took scientists still decades to develop the right tool to be able to measure its frozen coverage. It is possible to explore in winters and feel a part of nature, as nature has very carefully protected Lake Superior with its own special features.
The Fauna Around The Lake
Lake Superior is home to many varieties of wildlife — from fish, birds, reptiles, and amphibians to mammals such as bears, wolves, and lynx. The lake is also home to a wide array of aquatic plants, which provide essential food and shelter for many species.
The fish population in Lake Superior has been well-documented. Some of the common fish species found are walleye, lake trout, and cisco. The river otter also has a large population in the lake, although its exact number is unknown. Also common are the humpback chub, a species of minnow endangered in other parts of the world, and the lake sturgeon, a massive fish that can grow up to 6 feet in length. Other interesting aquatic species documented in the lake include freshwater jellyfish, eagles, ospreys, various types of herons, and even harbor seals.
The level of fauna activity around Lake Superior changes with the changing temperatures of the lake. For example, during periods of warmer water, fish species tend to move to shallower areas in order to feed, spawn and complete their life cycles. On the other hand, during periods of colder water, many of the fish and other species such as the lake sturgeon become less active and can be found much deeper in the lake where the temperatures are more stable.
Since the lake rarely completely freezes, it does not directly affect the wildlife, but it does cause some indirect changes. For example, rainfall and storms on the surface of the lake can create higher currents close to the edges, which can move the fish and other wildlife, causing them to go further away from their natural habitats and food sources. This makes it harder for them to find food and can cause a disruption in their population.
The Importance Of Lake Superior
Lake Superior is an incredibly important body of water and its significance reaches far beyond its size. It is home to a number of endemic species, some of which are endangered, while others can only be found in this region of the world. As such, Lake Superior plays an important role in preserving the biodiversity of the region.
The lake also provides a number of other services for the surrounding environment. It acts as a buffer for the local climate, helping to regulate temperature and also stores large amounts of freshwater. This makes the lake a crucial resource for the local communities as it helps them stay self-sufficient and also prevents water contamination from industrial and urban run-off.
Moreover, the lake serves as an important recreational resource for the area and its stunning surroundings draw millions of tourists each year. People come to Lake Superior for activities such as fishing, swimming, boating and other water sports. It is also one of the greatest sources of inspiration for many local artists, writers and musicians whose creativity is fuelled by the lake.
Lake Superior’s importance is not lost on its inhabitants, who have been living in and around the lake for generations. For these people, the lake has been a source of livelihood and sustenance, and continues to be so to this day.
Preserving Lake Superior
Given the great importance of Lake Superior, it is essential to ensure that it is preserved for future generations. There are a number of steps that can be taken to ensure that Lake Superior remains healthy and productive. One of these is to reduce the level of pollution entering the lake, especially from cities and other industrial areas.
It is also important to reduce the over-fishing of its species. For example, there are currently restrictions on the numbers and size of fish that one person can catch in the lake. Additionally, it is important to preserve the lake’s vegetation and reduce the invasion of invasive species. This can be done through education, increasing awareness of the lake’s importance and its vulnerability.
Finally, it is important to ensure that Lake Superior’s natural flow is maintained. This means reducing the amount of human-generated water discharged into the lake and the reduced use of water from the lake for human needs. In addition, reducing the amount of sediment discharge from building activities on land will help to maintain its clarity and health.
Conclusion
Lake Superior is a fascinating and resilient body of water that provides an abundance of resources for its local inhabitants. Its icy temperatures set it apart from other smaller lakes and rivers, and its unique ecosystem and relevance to the local communities make it an important part of preserving the region’s biodiversity. Ensuring that Lake Superior’s icy temperature persists, and preserving the lake’s health in general, will help to ensure that its importance continues to be offered to future generations.
