What Are Tides?
Tides are the rise and fall in sea level caused by the gravitational pull of gravitational forces from the Sun and Moon on the ocean. The Moon’s gravitational pull causes the greatest tide movements on the Earth, so the tides in any given area will depend on the Moon’s location and its distance from the Earth. Tides can range from a few inches to several feet. This is why it is important to have good tide charts for areas where marine activities take place.
Tidal Influences On Lakes
Most people think of the ocean as the only body of water that experiences tides, however, some bodies of water such as the Great Lakes can be influenced by the same gravitational forces that cause tides in the ocean. Even though the Great Lakes don’t experience the same large swings in water level like the ocean, they still experience changes in their water levels that can be accurately predicted by understanding the relationship between the moon’s position, the earth’s rotation, and the great lakes water levels.
Tides On Lake Superior
Lake Superior is the largest of the five Great Lakes, covering an area of nearly 31,700 square miles. Contrary to popular belief, Lake Superior does experience small tidal movements known as seiches. Seiches occur when the differing pressures of the Moon’s gravitational pull overcome the weight of the water, causing the basin to rise and fall. While these changes are barely perceptible to the average observer, they are nevertheless measurable and affect the lake’s water levels. The seiches in Lake Superior occur primarily in the northern portion of the lake on days with a full or new moon.
Seiches and Connectivity
One of the primary reasons that seiches occur in Lake Superior is the lake’s overall shape and its close connection to other bodies of water. The lake is surrounded by islands and peninsulas, and is connected to the other Great Lakes by two large waterway systems. This intricate network of connected waterways creates a system that allows water to move freely throughout the lake. As waves build in one area of the lake, they move towards other areas, allowing the lake’s water to rise and fall in a much greater array of points throughout the lake.
Seiches and Marine Life
The seiches in Lake Superior also have an effect on the lake’s aquatic ecosystem. The small changes in water level can cause drastic changes in the environment for aquatic species. For example, during periods of water level decline, large areas of lake bottom can become exposed, making them vulnerable to predation by birds and other animals. In addition, low water can also have a negative effect on the health of fish species by increasing the temperature of the water and reducing the oxygen content.
Human Influence on Lake Superior
The human influence on Lake Superior has also affected the seiches in the lake. For example, dams and other man-made structures on the waterways connecting Lake Superior to the other Great Lakes have caused a decrease in the exchange of water between the lakes. This has led to a decrease in the pressure exerted on the lake by the moon’s gravitational pull, resulting in smaller seiches and changes in water levels.
Seiches and Weather Patterns
Changes in weather patterns can also affect the size and frequency of seiches on Lake Superior. For example, during periods of warm weather when there is an increase in evaporation, the lake’s water levels tend to drop. Conversely, during times of heavy rains, the lake’s water level can rise significantly.
Conclusion and Summary
In conclusion, Lake Superior does experience small tidal movements known as seiches, which are primarily caused by the pull of the Moon’s gravitational forces. In addition, the lake’s overall shape and its connections to other bodies of water, as well as the human influence on the lake, all have an effect on the size and frequency of the Lake Superior seiches. Finally, changes in weather patterns can also have an influence on the lake’s water levels.
Effects Of Seiches
Seiches cause changes to the lake’s environment that can be beneficial and detrimental to the aquatic ecosystem. On one hand, they increase the oxygen content of the lake’s water, which is especially beneficial for fish. On the other hand, the changes in water level can make the lake prone to predation by other species such as birds.
Studying Seiches On Lake Superior
Studying seiches in Lake Superior involves understanding the interaction between the Moon’s gravitational forces and the shape of the lake. This is done by examining data such as the depth of the lake, the number of channels connecting the lake to other bodies of water, and the angle and size of Lake Superior’s basin. By understanding these factors, scientists can more accurately predict the size and frequency of Lake Superior’s seiches.
Managing Seiches In The Great Lakes Region
As the climate changes, the frequency and size of seiches in the Great Lakes region will also change. As a result, it is important for authorities to devise strategies that will reduce the risk of shoreline erosion and other damages attributed to extreme seiches. This often involves the implementation of shoreline stabilization measures such as breakwaters or submerged aquatic vegetation.
Economic Impacts Of Seiches On Lake Superior
The seiches on Lake Superior can have a significant impact on the local economy. For example, changes in the lake’s water level can alter the depths of local ports and marinas, making them inaccessible for vessels or even unsafe for navigation. This can lead to a disruption in business activity as well as a decline in tourism.
Human Activity Impact on Seiches
Human activity can also have an effect on the seiches in Lake Superior. For instance, overfishing can reduce the amount of nutrients in the lake, leading to a decrease in the lake’s oxygen content and an increase in water temperatures. In addition, excessive water pollution can lead to an increase in the lake’s acidity, reducing the habitats available for fish and other aquatic species.
