21 Shocking Facts About Lake Superior

Lake Superior is the largest, deepest, and coldest of the Great Lakes, but there’s much more to this incredible body of water than meets the eye. With a surface area larger than some countries, shipwrecks resting on its floor, and a reputation for sudden, violent storms, Lake Superior holds countless surprising, mysterious, and even eerie secrets.

From its unique geography and extreme weather patterns to its historical significance and ecological wonders, this list of 21 shocking facts will give you a whole new appreciation for one of North America’s greatest natural wonders.

1. Largest Freshwater Lake by Surface Area

Lake Superior is the largest freshwater lake in the world by surface area, covering approximately 82,100 square kilometres. To put that into perspective, it is bigger than the entire country of Austria and could hold all the other Great Lakes combined, with room to spare.

Despite its massive size, it is only the third-largest freshwater lake by volume, trailing behind Lake Baikal in Russia and Lake Tanganyika in Africa. However, its vast surface area contributes to its unique weather patterns and powerful storms.

2. Holds 10 Percent of the World's Freshwater

Lake Superior contains an estimated 12,100 cubic kilometres of water, which accounts for about 10 percent of the world's available surface freshwater. This is enough water to cover all of North and South America in roughly 30 centimetres of water.

Because of its immense size, the lake has an incredibly slow turnover rate. It takes about 191 years for a single drop of water to travel through Lake Superior from one end to the other before it moves on through the Great Lakes system.

3. Home to Over 350 Shipwrecks

The unpredictable weather, sudden storms, and powerful waves have led to the sinking of over 350 ships in Lake Superior. Some of the most famous wrecks include the SS Edmund Fitzgerald, which sank in 1975 with all 29 crew members lost.

Many of these shipwrecks remain well-preserved due to the lake’s cold, deep waters. Divers frequently explore the wreckage of sunken vessels, and some are part of underwater preserves for historical and research purposes.

4. Its Water is Incredibly Cold Year-Round

Even in the middle of summer, Lake Superior remains shockingly cold. Surface temperatures in July and August rarely exceed 15 degrees Celsius, while deeper parts of the lake stay near freezing throughout the year.

Because of these frigid temperatures, the lake has a reputation for being extremely dangerous to swimmers. Hypothermia can set in within minutes, and even experienced swimmers can struggle with the sudden shock of cold water.

5. Can Create Waves Over 9 Metres High

Lake Superior can generate waves as high as ocean swells, reaching over 9 metres during severe storms. These towering waves have contributed to the sinking of numerous ships and continue to make the lake one of the most unpredictable and dangerous bodies of water in North America.

Strong winds and the lake's immense size create conditions similar to those found on the open ocean. Many mariners have described the lake as having a mind of its own, with waves appearing seemingly out of nowhere.

6. Freezes Less Than Other Great Lakes

Despite its location in a cold climate, Lake Superior does not freeze over completely as often as the other Great Lakes. This is due to its incredible depth, which prevents the entire surface from freezing solid.

However, in particularly harsh winters, the lake has been known to freeze almost entirely. The last time this happened was in 2014, when nearly 95 percent of the lake was covered in ice.

7. Home to One of the Oldest Rocks on Earth

The Canadian Shield, which forms much of Lake Superior’s surrounding landscape, contains some of the oldest known rocks on Earth, dating back around 2.7 billion years. These ancient rocks provide insight into the planet’s early history and geological evolution.

Some of these formations, such as the Agawa Rock Pictographs in Ontario, also hold deep cultural and spiritual significance for Indigenous peoples who have lived in the region for thousands of years.

8. Can Create Its Own Weather

Due to its enormous size, Lake Superior has a direct impact on local weather patterns. It can generate lake-effect snow, where cold air moving over the warmer water picks up moisture and releases it as intense snowfall over nearby land.

The lake also has a moderating effect on temperatures, keeping coastal areas cooler in summer and warmer in winter. This unique climate influence makes the surrounding regions distinct from the rest of Ontario, Michigan, Minnesota, and Wisconsin.

9. More Than 200 Rivers Flow Into It

Lake Superior is fed by more than 200 rivers and streams, with some of the largest contributors being the St. Louis River, the Nipigon River, and the Pigeon River. These waterways play a vital role in maintaining the lake's water levels and ecosystem.

Despite the vast number of inflowing rivers, there is only one natural outlet: the St. Marys River, which connects Lake Superior to Lake Huron. This narrow channel plays a critical role in controlling water levels across the entire Great Lakes system.

10. Contains Unique Underwater Caves and Cliffs

Lake Superior’s underwater landscape is as dramatic as its coastline, with submerged cliffs, deep trenches, and hidden caves. The lake’s rugged underwater formations attract divers and researchers eager to explore its mysterious depths.

One of the most well-known spots is the Devil’s Warehouse, an underwater cave near Isle Royale that has fascinated divers for years. These hidden formations add to the lake’s mystique and continue to be a source of discovery.

11. The Lake Can Take Lives Without Returning Bodies

Due to the extreme cold and depth of Lake Superior, bodies of those who drown are often never recovered. Unlike in warmer waters where decomposition gases can cause bodies to rise to the surface, Lake Superior’s frigid temperatures prevent this process.

Many victims remain at the bottom, perfectly preserved due to the lake’s unique conditions. This has led to eerie legends and stories about ghosts of sailors lost to the depths.

12. Has a Deepest Point of 406 Metres

The deepest point of Lake Superior reaches a staggering 406 metres, making it the deepest of all the Great Lakes. To put this into perspective, the CN Tower in Toronto is 553 metres tall, meaning you could submerge most of it into the lake.

This extreme depth contributes to its vast water volume and slow temperature changes. Even in the summer, deeper sections of the lake remain near freezing year-round.

13. Holds Enough Water to Cover North and South America

If the water in Lake Superior were spread evenly across North and South America, it would cover the entire landmass in approximately 30 centimetres of water. This staggering amount showcases just how much freshwater the lake contains.

This vast water reserve plays a critical role in the environment and water supply of the Great Lakes region. However, its sheer size also makes it vulnerable to pollution and climate change impacts.

14. Has an "Underwater Forest" of Preserved Trees

Due to the cold temperatures and lack of oxygen at great depths, entire forests of ancient trees remain preserved on the lake bottom. These submerged forests date back thousands of years, offering a rare glimpse into past climates and ecosystems.

Scientists have found trees that appear as though they were recently cut, despite being underwater for centuries. These frozen-in-time forests are just one of the many hidden wonders lurking beneath the surface.

15. Once Had a "Silver Tsunami" of Fish

In the early 20th century, Lake Superior was home to an overwhelming population of cisco fish, also called lake herring. During their spawning seasons, the sheer number of fish was so massive that waves would push thousands of them ashore, creating what was called a “silver tsunami.”

This phenomenon supplied communities with an abundance of fish, but overfishing and ecological changes have since reduced the cisco population significantly. Conservation efforts continue to try to restore their numbers.

16. The Lake Can Have "Ice Volcanoes" in Winter

During winter, the freezing lake water combined with powerful waves can create "ice volcanoes" along the shoreline. These formations occur when waves force water up through cracks in the ice, creating cone-shaped structures that resemble volcanic eruptions.

These ice volcanoes are a striking natural sight but can be dangerous. Walking on them is risky, as they can collapse unexpectedly, plunging people into the icy waters below.

17. Home to the Mysterious "Superior Shoal"

Beneath the lake’s surface lies the Superior Shoal, a submerged mountain range that rises nearly 150 metres from the lakebed. This hidden underwater ridge remains largely unexplored and poses a danger to ships.

Many believe undiscovered shipwrecks lie within this treacherous area. Its sudden elevation change makes it one of the lake’s most intriguing geological features.

18. Contains Ancient Copper Deposits

Indigenous peoples mined pure copper from the Lake Superior region thousands of years ago, long before European settlers arrived. These deposits contributed to early trade networks and tool-making for many cultures.

Some underwater copper deposits remain, hinting at even more ancient mining activity. The lake’s history as a mineral-rich region has played a key role in shaping industries around it.

19. Home to the Largest Freshwater Island in the World

Lake Superior is home to Isle Royale, the largest freshwater island in the world. This island, located in U.S. waters, is a national park known for its rugged beauty, moose population, and isolated wilderness perfect for backcountry camping.

Despite its size, Isle Royale is one of the least-visited national parks in the U.S., making it a true hidden gem for those seeking solitude and adventure.

20. Has a "Singing Sands" Beach

Near the town of Rossport, Ontario, certain sandy beaches around Lake Superior have a strange phenomenon where the sand produces musical sounds when walked on. This rare occurrence, known as “singing sand,” happens due to the unique composition of the grains.

Not many people know about this hidden wonder, but those who experience it describe it as a magical and otherworldly sound.

21. The Lake is Home to Unique Species

Lake Superior hosts several species that are found nowhere else in the world. The Lake Superior whitefish, prized for its delicate flavour, thrives in the lake’s cold waters. Another notable species is the endangered Lake Sturgeon, which can live over 100 years and grow up to 2.5 metres in length. Conservation efforts are in place to protect these unique creatures, as they play a vital role in maintaining the lake’s ecosystem.

The lake also supports a variety of other aquatic life, including algae, plankton, and invertebrates, which are crucial to the food web. Researchers continue to study these species to understand how they adapt to the lake’s cold and nutrient-rich environment. As environmental challenges rise, preserving these unique species has become essential to protecting Lake Superior’s biodiversity.

Final Thoughts

Lake Superior is truly a remarkable natural wonder, from its vast size and crystal-clear waters to its rich history and unique ecosystem. Whether you’re exploring its rugged shoreline, learning about its ancient geological origins, or marveling at its pristine environment, there’s no denying the lake’s awe-inspiring presence. As the largest and deepest of the Great Lakes, Lake Superior continues to captivate those who venture into its waters and surrounding landscapes.

While it offers endless opportunities for adventure and discovery, it also serves as a reminder of the power and mystery that lies beneath the surface. Preserving this natural treasure is essential to ensuring future generations can continue to experience its beauty and learn from the incredible stories it holds. Lake Superior will always remain a symbol of both the wild, untamed forces of nature and the quiet, enduring wonders of our planet.