How did the Great Lakes get so deep?

The Great Lakes were born when glaciers receded from this part of the world at the end of the last ice age. As the icy bulldozers went northward, they carved out deep troughs in the earth that later filled with water.

What keeps the Great Lakes filled?

Due to their vast volumes, the lakes cool slowly through the fall, when evaporation increases into the cooler, drier air. Ice cover, which varies from year to year, curbs evaporation during the cold months. The past 10 years have been the wettest on record for the Great Lakes watershed.

How were the Great Lakes actually formed?

Simply put, the Great Lakes were created by glaciers. About 18,000 years ago, the Laurentide glacier covered most of Canada and the Northern U.S. As the glacier moved, it flattened mountains and carved valleys. It's estimated that the glacier was nearly 2.5 miles thick.

What's at the bottom of Lake Superior?

After searching more than 2,500 miles of the bottom of Lake Superior, the Atlanta — a 172-foot schooner-barge that sank during a terrible storm — has been found, preserved in the icy water just as it was when it went down more than 130 years ago. Even the gold letters of the ship's nameplate are still visible.

What existed before the Great Lakes?

before present, during the last glacial period called the "Wisconsian". The lakes which we now call Superior, Michigan and Huron were part of two vast inland lakes called "Lake Duluth" and "Lake Algonquin". These lakes were later joined as the glaciers retreated to form one vast lake.

What’s so great about the Great Lakes? - Cheri Dobbs and Jennifer Gabrys

Was Lake Erie an ocean?

It was one of the first Great Lakes to be uncovered during the last retreat of the glacial ice. The oldest rocks from which the Lake Erie basin was carved are about 400 million years old and formed in a tropical ocean-reef environment. Lake Erie and its shoreline are a major source of many minerals.

Why is Lake Superior not a sea?

The Great Lakes could be considered a failed ocean. They are in a place where rifting started to create a new ocean, but it never got connected to the ocean system (and flooded), and that was still the case when the rifting eventually stopped. Those rifts were then further (much later) "excavated" by glaciers.

Why are the Great Lakes not salty?

"The Great Lakes are not (noticeably) salty because water flows into them as well as out of them, carrying away the low concentrations of minerals in the water," writes Michael Moore of Toronto. Eventually, this water, with its small load of dissolved minerals or salts, reaches the sea.

Is there an underground lake under Lake Superior?

As we determined this past week with several arduous dives, the caves lead to a vast underground lake. This is undoubtedly Sir Duluth's 'Lac d'Enfer,' and the same lake which swallowed poor William Bitter in 1870.

Could a tsunami happen in the Great Lakes?

“Meteotsunamis happen in every Great Lake and they can happen (roughly) 100 times per year,” said Eric Anderson, the study's lead author and a scientist with the National Oceanic and Atmospheric Association's Great Lakes Environmental Research Laboratory.

Who owns the water in the Great Lakes?

The water in the Great Lakes is owned by the general public according to the Public Trust Doctrine. The Public Trust Doctrine is an international legal theory – it applies in both Canada and the United States, so it applies to the entirety of the Great Lakes.

Are any of the Great Lakes saltwater?

Lakes Erie and Ontario have the highest salinity readings, while Lake Superior is lowest with only l or 2 milligrams of salt per liter of water.

Do the Great Lakes freeze?

Typically, more than half of the Great Lakes freeze each winter.

Why dont the Great Lakes dry up?

Warmer-than-average winters since 1998 kept smaller lakes free of ice for longer time spans, allowing more water to escape through evaporation.

Are there sharks in the Great Lakes?

The water temperature in the Great Lakes is far too cold for most sharks (including the Bull Shark). Even if it managed to make it through the summer months, our frigid winters would turn it into a “sharksicle” in no time.

What source feeds the Great Lakes?

The lakes were originally fed by both precipitation and meltwater from glaciers which are no longer present. In modern times, only about 1% of volume per year is "new" water, originating from rivers, precipitation, and groundwater springs.

Is there a volcano under the Great Lakes?

Lake Superior sits on top of a massive… I mean massive volcano. Our five Great Lakes may have been formed by Ice Age glaciers, but volcanic activity was instrumental in giving us Lake Superior.

Are there sea monsters in Lake Superior?

In Lake Superior, near the Presque Isle River, the creature is called Pressie. Over the past 400 years, there have been numerous sightings of Pressie. In one famous published story, a copper prospector came across the creature in an underwater cave in Lake Superior.

Have we explored the bottom of the Great Lakes?

Scientists making the first submarine expedition in Lake Superior have had their first look at the bottom at its deepest -- more than 1,300 feet -- and found it teeming with life, though only of three species.

Are there whales in the Great Lakes?

Whales don't live in the Great Lakes. Or do they? No, not at all.

Can you drink Great Lakes water?

The Great Lakes are an extremely important water source to Canadians and Americans, as well as to the world. It is very important that the lakes be protected, so that they can continue to provide safe drinking water for the 35 million people in the Great Lakes region, as well as sustainable industry and agriculture.

Can you sail from Great Lakes to ocean?

Lock infrastructure on the Great Lakes and St. Lawrence Seaway forms an elaborate lift system allowing ships to move across a vast expanse of territory in which water levels fall more than 182 m (600 feet) from Lake Superior to the Atlantic Ocean. During that journey, a vessel will pass through 16 separate locks.

What's the biggest fish in Lake Superior?

Lake sturgeon are the largest fish in Lake Superior. They among the oldest fish in the lake too. Did you know that a lake sturgeon can live to be older than 100 years? This species of fish has also been around for a long time—about 150 million years.

Do the Great Lakes have tides?

True tides—changes in water level caused by the gravitational forces of the sun and moon—do occur in a semi-diurnal (twice daily) pattern on the Great Lakes. Studies indicate that the Great Lakes spring tide, the largest tides caused by the combined forces of the sun and moon, is less than five centimeters in height.

Can you swim across Lake Superior?

A Canadian woman has become the second person to swim across Lake Superior, from Orienta in Bayfield County to Two Harbors. Paula Stephanson, 28, of Belleville, Ontario, finished the 20-mile swim about 7:40 p.m. Saturday after 13 hours and 15 minutes in the water. The swim was Stephanson's fourth Great Lakes crossing.