Scientific Explanation
Lake Superior is the largest of the Great Lakes with a surface area of 31,700 square miles. Interestingly, it is also the deepest lake in North America and the world’s largest lake by area; containing 2,900 cubic miles of water. Its deep waters are regarded as a potentially hazardous environment due to its extreme depths and the fact that much of the lake remains unexplored. As such, the thickness of the ice on Lake Superior is a key factor in determining the safety of any activity conducted upon it.
Generally speaking, the average thickness of the ice on Lake Superior is a little more than 30 inches. However, it is important to note that the actual thickness of the ice in different areas can vary significantly based on a number of factors such as temperature, wave action and sunlight. For instance, on days when the temperature is particularly cold, the ice on the lake is likely to be thicker than normal due to the freezing temperatures.
In addition, wave action and sunlight can also affect the thickness of the ice on Lake Superior. If the lake is particularly choppy or exposed to direct sunlight, the ice will begin to melt and thin out. This thinning process can make the lake unsafe as areas where the ice is thin or has melted altogether may collapse underfoot or vehicle. Moreover, since Lake Superior is so deep, windows or fractures in the ice can form due to the additional pressure and stress of the large body of water pressing down on it.
Safety Considerations
Due to the thinning and fracturing of the ice on Lake Superior, it is important for people to exercise caution when conducting activities on the lake during the winter months. Most often, this involves making sure that the ice is thick enough to support the weight of any individuals or vehicles that will be travelling on it. Generally speaking, a minimum of four inches of ice is necessary for most activities, with more substantial ice thickness necessary for larger vehicles.
The general rule of thumb is that the more people or vehicles that will traverse the ice, the thicker it should be. At a minimum, a safe recommendation is for the ice to be at least 4–5 inches thick for a single person, 8–12 inches thick for a snowmobile, and 12–15 inches thick for a car or light truck. The thickness should also be verified in different areas of the lake, as the ice can be significantly thinner in certain areas.
Furthermore, it is also essential to pay attention to any warning signs. Nipigon District Council, for example, has installed a variety of warning signs along the shorelines of Lake Superior which provide users with information on the minimum thickness requirements for various vehicles, as well as messages warning of thin or unsafe ice conditions.
Techniques for Measuring Ice Thickness
Another factor to consider when gauging the ice thickness on Lake Superior is the ability to accurately measure the ice thickness. Many people rely on the “spud bar test”, which involves taking an eight-foot spud bar and thrusting it into the ice. This method helps determine the depth of the ice and reveals any cracks that may be present beneath the surface, as well as any other classic signs of inadequate ice thickness.
However, this technique is not always reliable. For this reason, advanced methods such as an ice core sampler usually provides the most accurate information when determining the thickness of the ice. This technique involves taking a cylindrical core of the ice and measuring its thickness with a tape measure. This method is the most reliable and can help provide peace of mind in knowing the ice is thick enough to support a vehicle or individual.
Preventative Measures and Preparations
When travelling on Lake Superior during the winter months, it is also important to take preventative measures and make sure to be prepared for an emergency. Travellers should always wear a life jacket, dress appropriately and have the proper supplies in their vehicle or on their person, such as flares, rope, a shovel and a cell phone. Furthermore, it is also beneficial to notify someone of your location, any planned route and other important details in the event that help is needed.
Additionally, it is important to have an escape plan in place should an emergency arise while on the ice. Travellers should know the location of the nearest shoreline and any immediate hazards such as open water or thin ice, as well as plan an escape route in the case that the ice should break beneath them.
Conclusion
In conclusion, the thickness of the ice on Lake Superior is an important factor to consider when conducting activities on the lake during the winter months. The average thickness of the ice on the lake is roughly 30 inches but can vary significantly depending on the weather, wave action and other conditions. To ensure safety, it is important to be aware of the minimum thickness requirements for various activities, accurately measure the ice thickness, as well as take necessary preventative measures for an emergency.
