Introduction
Lake Superior is the largest of the five Great Lakes. It is known for its deeply cold temperatures, especially in its depths. Therefore, it’s no surprise that the question of how cold the bottom of the lake is arises. This article seeks to explore the temperature of the deepest parts of this lake, and understand the process of what makes the lake so cold.
Reaching Depths of Cold
The depths of Lake Superior extend far below the surface, reaching depths of up to 400 feet. While the surface of the lake may be as warm as 75 degrees Fahrenheit during the summer months, the water temperature in the depths of the lake can reach as low as 39 degrees Fahrenheit. This is significantly colder than the normal water temperature of spring and fall, which averages around 59°F.
Not only does the temperature at this depth stay consistently cold throughout the year, but further down the pressure becomes much higher. As one goes deeper, the pressure increases exponentially, intensifying the cold even further.
Factors Affecting Lake Temperature
The temperature at the bottom of Lake Superior is primarily a product of its depth, pressure, and geographical location. The lake lies in the far northern reaches of the North American continent, which experiences its own bitter cold weather even during the summer season. This colder air temperatures also affect the temperature of the lake itself.
In addition, the water at the surface is cooled in the winter by frigid air temperatures and the still depths of the lake, which provide insulation. This cools the water, which creates a layer at the surface that sinks to the bottom of the lake and helps keep the temperature very low.
Moreover, the lake is extremely deep and its size means that the volume of water is large which also contributes to its cold temperature. Because of the vast volume of water, it can take a long time for the lake to warm up or cool down. This means that it will remain cold in the depths for a long time.
Impact of Cold Depths on Lake Ecosystems
The effect of the extreme temperatures in the depths of the lake has an impact on the lake’s ecosystem. Due to the cold temperatures, the organisms living within the lake have adapted in order to survive. These types of organisms include aquatic plants, worms, insects, and fish.
In addition, the extreme cold water temperature can also bring about a decrease in the abundance of these species due to the cold environment. The organisms must be able to tolerate the extreme cold conditions in order to survive.
Conclusion
As Lake Superior is the largest of the Great Lakes, its depths are naturally colder but due to factors such as depth, pressure, and geographical location the water temperature can reach as low as 39 degrees Fahrenheit, significantly colder than the normal temperature of 59°F. Additionally, the cold depths have an impact on the lake’s ecosystem, to which organisms found in the lake must be able to tolerate the extreme cold conditions. All together, the bottom of Lake Superior is confirmed to be a deep pool of immense, cold water.
Geothermal Activity
Lake Superior is home to a unique—albeit rare—geothermal activity. The lake’s basin is heated by the Earth’s core, resulting in water temperatures that remain remarkably constant, even when air temperatures outside the lake fluctuate. The steady temperatures of the lake, due to geothermal activity, are estimated to reach temperatures between 43°F and 46°F, depending on the season and location within the lake.
The geothermal activity located in the lake is only present in certain locations. The spots that experience this heating are found on the lake floor in the form of vents, referred to as hydrothermal vents. These vents release hot, chemically-rich fluids that are produced from the Earth’s inner heat. The combination of the geothermal activity and the colder water coming from the surface creates pockets of warm water.
This geothermal activity is relatively rare, considering Lake Superior is the largest of the five Great Lakes. It is estimated that less than 10 of these vents are located on the floor of Lake Superior, making it the only spot in the Great Lakes with this type of activity.
Effects of Temperature on Lake Life
The extreme cold conditions of the bottom of the lake can have a major impact on the organisms living in the lake. Fish spawn and seek refuge in the warmer waters of the lake, while other organisms — such as worms, crustaceans, and insects — live in the cold depths of the lake.
Warm-water species are able to tolerate the cold waters of the lake near the surface, but find it difficult to survive in the even colder depths. Cold-water species, on the other hand, are better suited for living in the deep water and are able to tolerate the cold temperatures.
The cold temperatures of the lake also cause some organisms to migrate. As the temperatures drop in the winter, some fish migrate to the warmer waters at the surface or the estuaries of the lake, where temperatures remain relatively mild.
Impact of Temperature on Dredging
Extreme cold temperatures and pressure can also have a negative impact on dredging activities, due to the stress it puts on dredging equipment and structures. To ensure dredges and other structures remain functional and safe, they must be able to withstand cold temperatures and high pressures. This can be difficult and costly.
In order to avoid any damage to the dredges or other structures, companies take extra steps in making sure their equipment is properly insulated and sealed to ensure that heat-sensitive components are not affected by the cold. Even then, care must be taken to make sure that ice does not form on the surface of the equipment. This can be very difficult to accomplish in the depths of the lake due to extreme cold temperatures.
In addition, dredging operations conducted in the lake often require the use of specialized equipment and techniques to withstand extreme water pressures. Divers also need to be trained to be protected from the intense cold. Thus, cold temperatures of Lake Superior can make dredging activities very costly and difficult.
Saving the Ecosystem
The cold depth of Lake Superior is a complex phenomenon that has a direct influence on the aquatic life in the largest of the Great Lakes. To help protect the fragile ecosystem of the lake, regulatory measures have been put in place to limit the strain that dredging activities may cause on the lake bottom. In addition, special care must be taken to limit the amount of pollutants entering the lake as this can add to the environmental stress that aquatic life is exposed to.
In addition, efforts have been taken to help conserve and protect the native species of the lake. Through reintroduction and monitoring of fish stocks and encouraging sustainable practices, the species living in Lake Superior are now doing much better.
Local organizations also work to raise awareness about the lake and what can be done to help protect it, including advocating for better regulations and policies to keep the lake healthy and clean. Through these efforts, Lake Superior can remain the icy depths it is known for and remain a source of both pleasure and pride for the people living in its line of sight.
