How old are the Great Lakes?
The Great Lakes formed around 3,000 years ago near the end of the last ice age. Whether you are a US native or live internationally, you have likely heard of the Great Lakes. This group of five lakes makes up the largest freshwater region in the world, with over 21% of the entire surface supply of the earth being found within. The five lakes are Lakes Superior, Michigan, Huron, Erie, and Ontario and have a collective surface area that measures 94,250 square miles, roughly the size of the state of Oregon (96,003 square miles). The Great Lakes are somewhat newer lakes when you compare them to the rest of the world. At only 14,000 years old, the Lakes were formed while humans walked the earth. Incredibly, humans likely walked the Great Lakes region as they were forming. Despite most of geologic history being on a different scale of time than the human species, the Great Lakes are a unique exception.
What made the Great Lakes?
The forces needed to create such massive bodies of water are truly immense and are actually still around today! The Great Lakes, along with most of the other lakes in the immediate region, were formed when the Last Glacial Period (otherwise known as an ice age) ended and the earth began to warm. During the period of warming, the ice sheets that covered the northern part of the United States began to withdraw. As the continent-size ice sheets receded, they left deep gauges in the earth. At the same time, the receding glaciers (ice sheets) poured their melting water into these deep gauges in the earth. Over a few thousand years, you have what we today call the Great Lakes! This process wasn’t fast, however, and didn’t even happen all at once. In fact, there were four different advances and recessions of the ice sheets, each having a different impact on the region’s geologic history. The final expansion of the ice sheets is referred to as the Wisconsin glaciation and ended around 10,000 years ago.
Which Great Lake is the oldest?
When the Great Lakes formed, they are generally considered to have formed together, all at once. Still, there is some data we can look through that can give us an idea as to which of the five came first. During the final period of glacial expansion in the region, the Wisconsin glaciation, massive lobes of ice came forward and receded. Only this time, the drainage of the glaciers was faster than in the other periods. This caused water to fill in the sloped land near the foot of the glaciers, causing large crescent-shaped lakes to form. The largest of these lakes, Lake Maumee, covered the northwest corner of Ohio and reached into Indiana. As time went on, these lakes would combine into one another, and the first lake of the Great Lakes would be free from under the ice. This crescent-shaped lake is today known as Lake Erie.
What is the oldest lake in the world?
Although the Great Lakes aren’t that old, they are quite large. Still, there is a lake on the other side of the world that is older, larger, and deeper than any one of the Great Lakes! Located in Siberia, Lake Baikal may just be the ultimate record holder of all the earth’s lakes. Lake Baikal is the largest freshwater lake in the world by volume, even if you added each of the Great Lakes together! Additionally, it holds the record as the world’s oldest lake, with an estimated age of 25-30 million years old. If that wasn’t enough, it’s also the world’s deepest lake, measuring 5,387 feet at some points. Where the Great Lakes were formed by glaciers, Lake Baikal was formed by tectonic activity. Since tectonic activity is much deeper in the earth (when compared to glaciers) and operates over a much slower span of time, it’s no wonder that Lake Baikal holds all the records. The lake is located in a rift valley where the earth’s crust is slowly being pulled apart.
How long have humans been living around the Great Lakes?
The best guess as to when humans first arrived in North America is currently around 20,000 years ago. When a large land bridge formed after freezing water was pulled into a glacier, humans likely walked or partially sailed through the Beringia Strait from Russia into modern-day Alaska. It took some time for Native Americans to make it all the way east to the Lakes, but when they did, they found a fertile land filled with wildlife. Current estimates have humans arriving in the Great Lakes basin around 10,000 years ago. Within 4,000 years, humans were using copper dug from the southern shores of Lake Superior, as seen around the Keweenaw Penninsula. Settlers in the region grew corn, squash, beans, tobacco, and harvested wild rice. When the first colonists arrived in the region around 1620, the population of the Great Lakes region was estimated to be between 60,000 and 117,000.
