At 10,000 square miles, Lake Superior is the largest freshwater lake in North America by area. It’s a popular destination for marine recreation and as a source of drinking water, but it’s also known for its cold waters, even in the summer. During the winter months, Lake Superior can often freeze completely, although the extent of this freeze and the actual amount of time the lake is frozen vary widely, depending on the weather at hand.
The US Geological Survey regularly tests the waters of Lake Superior and tracks its air and water temperatures throughout the year. In general, the lake generally starts to freeze at its northern shore sometime during December and then gradually spreads southward until, by mid-to-late January, all of the lake is frozen. By late February or early March, the lake typically begins to thaw, although in some years the lake can remain frozen through April and even into May.
The actual thickness of the ice varies depending on the year and the region. Generally speaking, the ice around the shore tends to be thicker (up to 16 inches or more) than the ice further out, which tends to be less than 8 inches. That said, the amount of ice on the lake can vary significantly and can be affected by many factors, such as local air temperatures, wind direction and speed, and the amount and type of snowfall.
Temperature of Frozen Lake Superior
Although it’s not an exact science, there are some interesting relationships between temperature, snowfall, and freeze. In general, air temperatures below -20 degrees Fahrenheit likely cause Lake Superior to start freezing from its northern shore, while temperatures rising above 32 degrees Fahrenheit will cause it to thaw. Additionally, more snowfall tends to result in thicker ice and a longer freeze period, which is why Lake Superior often stays frozen through April and into May in some years.
For instance, in 2016, Lake Superior froze completely because of especially cold temperatures and an above-average snowfall, while in 2017 and 2018, a much milder winter meant the lake didn’t freeze nearly as much or as thickly. However, while temperatures in 2019 were similar to those of 2017 and 2018, the above-average snowfall meant that the lake froze a lot more. That said, it’s important to remember that there are other factors at play and that these patterns don’t always hold true.
Experts Perspective on Frozen Lake Superior
Experts in climatology and lake science are keeping a close eye on the state of frozen lake Superior. They’re concerned that changing weather patterns due to climate change could mean that Lake Superior doesn’t freeze as often or as thickly in the future, which could have potentially devastating effects on the local ecology of the lake.
Dr. Garnet Wipperfurth is a professor of climatology at the University of Michigan who studies the effects of climate change on freshwater lakes. She explains that a decrease in the amount of freezing could mean more algae blooms, since warmer waters with less ice cover provide a better environment for the growth and survival of some types of algae. That, in turn, could lead to reduced oxygen levels in the water, fewer fish, and reduced biodiversity.
Dr. Wipperfurth also notes that a decrease in the amount of ice could mean that the lake absorbs more of the sun’s heat energy during the summer, resulting in higher water temperatures and poor water quality. Not to mention that it could result in reduced shoreline integrity, since ice is a major source of sediment for the lake’s shoreline.
Effects of Global Warming on Frozen Lake Superior
As the global climate continues to warm, experts worry that Lake Superior will freeze less and less in the future. According to the latest data, air temperatures in the region have increased 2.3 degrees Fahrenheit over the past 50 years and are expected to continue to rise. This could mean significantly shorter and less severe winter freeze periods, which could have major ramifications on the lake’s ecology.
Dr. Wipperfurth explains that “models suggest that, in the future, the lake will freeze much less and thaw earlier. This could result in drastic changes to the lake’s food web, as well as changes to other aspects of its ecology, like the availability and distribution of sediment, the water’s temperature, and its clarity and plant life.”
Furthermore, she notes that these changes could also have an impact on the local economy. “The lake is a major source of drinking water for the region and is an important source of recreation and tourism,” she says, “so any changes that disrupt the lake’s ecology could have serious economic consequences as well.”
Melting of the Frozen Lake Superior
The thawing or melting of the Lake Superior ice cover happens through several different processes. Solar radiation and air temperature are the two main factors, as they both play a role in causing the ice to sublime or melt.
However, there are also other factors at play, such as wind and snow cover. Wind can help stir up the waters and break up the ice, while snow cover can insulate the ice and help it retain its structural integrity by blocking solar radiation. As a result, the amount of snowfall and the winds experienced on the lake can play a major role in how quickly the lake thaws.
The US Geological Survey also notes that there are some large-scale oceanic processes at play, too. For instance, during El Niño events, Lake Superior tends to thaw earlier, due to warmer ocean waters to the south and southwest of the lake. Additionally, the US Geological Survey notes that this melting process can be further influenced by large storms and storm systems prevalent in the spring, which would likely lead to faster thaws.
Weather Conditions Affecting the Frozen Lake Superior
The weather conditions that affect the freeze and thaw of Lake Superior vary from year to year and can be affected by the global climate and local conditions. For instance, in 2016, one of the lake’s coldest winters ever, temperatures plunged to -20 degrees Fahrenheit, while in 2017 and 2018, much milder winters resulted in a much shorter and less thick freeze.
The amount of snowfall and wind speed are also important factors. In general, more snowfall tends to result in thicker ice and a longer freeze period, while extreme winds can help disperse the ice more quickly during the thaw period. That said, the exact weather conditions can vary from year to year, so it’s important to keep a close eye on them.
Conservationists and lake experts also note that climate change could have an increasingly significant impact on the lake’s freeze and thaw cycle in the future. Warmer air temperatures, for instance, could mean a much shorter and thinner ice period, which could have serious consequences for the lake’s ecology and economy.
Managing the Frozen Lake Superior
In order to manage and protect the frozen Lake Superior, the local authorities and conservation groups have put in place several measures aiming to safeguard the lake and its surrounding environment.
For instance, they have set up ‘ice patrolling’ programs, where volunteers travel out onto the lake to measure the ice thickness and report any irregularities or weak spots. Additionally, the local authorities have implemented an education campaign, aimed at teaching locals about the importance of protecting the lake’s ecology during its freeze and thaw periods.
Moreover, the US Geological Survey is keeping an eye on the lake’s air and water temperatures, and conducting regular ice thickness measurements in order to better understand how the freeze and thaw cycle works. This data, they hope, will help them better predict future freeze and thaw cycles, allowing them to put in place measures to protect the lake’s ecology.
Maintenance of the Frozen Lake Superior
Apart from the initiatives put in place to protect the lake’s ecology, the local authorities take measures to ensure the lake is kept clean and safe during its frozen period. This includes regular clean-ups of the lake’s shores, where volunteers remove any garbage and hazardous materials. These clean-up efforts are critical for the health of the lake, as garbage and pollutants can seep into the water if left unchecked.
Additionally, the local authorities perform regular checks on the ice thickness and its structural integrity, in order to ensure that the lake is safe for recreational activities during its frozen period. This is especially important for activities like ice fishing, which are popular within the region. That said, it’s important to remember that safety should always be the top priority when engaging in activities on a frozen lake, as the ice is unpredictable and can break at any moment.
Preservation of Frozen Lake Superior
In addition to the initiatives aimed at protecting the ecology and safety of Lake Superior during its frozen period, the local authorities also take steps to preserve and protect the lake’s natural beauty. This includes measures to safeguard the lake’s habitat, such as prohibiting the destruction or destruction of the lake’s shores, as well as restricting access to certain areas of the lake.
Furthermore, they regularly test the lake’s water to check the quality of its drinking water and to ensure pollutants are being kept to a minimum. Moreover, they aim to manage the lake’s resources responsibly, by implementing strict regulations on fishing and other activities that could negatively impact the lake’s environment.
Finally, the US Geological Survey is constantly monitoring the lake’s air and water temperatures, ice thickness, and freeze and thaw cycles in order to better understand how the lake’s environment is changing. These data, they hope, will help them better predict future freeze and thaw cycles, allowing them to take even more effective measures for protecting the lake.
