Lake Ontario is one of the five Great Lakes of North America.
It is surrounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the American state of New York, whose water boundaries meet in the middle of the lake.
Lake Ontario is the 14th largest lake in the world in terms of surface area.
Lake Ontario is the smallest of all the Great Lakes in surface area (18,960 square kilometers / 7,340 square miles), but its waters run deep.
Lake Ontario holds about four times the water volume (1,640 cubic kilometers / 393 cubic miles) as Lake Erie, although it is similar in width and length.
It ranks fourth among the Great Lakes in maximum depth (244 meters / 802 feet), but its average depth (86 meters / 283 feet) is second only to Lake Superior.
Its maximum length is 311 kilometers (193 miles) and its maximum width is 85 kilometers (53 miles).
Lake Ontario has an elevation of 74 meters (243 feet) above sea level; ; 99 meters (326 feet) lower than its neighbor upstream (Lake Erie).
Lake Ontario has a retention time (the measurement of time that water spends in a particular lake) of about 6 years.
The drainage basin covers 64,030 square kilometers (24,720 square miles).
When its islands are included, the lake has a shoreline that is 1,146 kilometers (712 miles) long.
There are a number of islands on the lake, including the Thousand Islands region [photo below], which is an archipelago of 1,864 islands that line the U.S.-Canadian border. While many of the islands are small or even uninhabitable, the largest is Wolfe Island, which, at 124 square kilometers (48 square miles).
Baymouth bars built by prevailing winds and currents have created a significant number of lagoons and sheltered harbors.
Its primary inlet is the Niagara River from Lake Erie. Other major rivers draining into Lake Ontario include the Don River, the Humber River, the Trent River, the Cataraqui River, the Genesee River, the Oswego River, the Black River, and the Salmon River. [Photo: Niagara River meets Lake Ontario]
As with all the Great Lakes, water levels change both within the year (owing to seasonal changes in water input) and among years (owing to longer term trends in precipitation).
Close to 9 million people or over a quarter of Canada’s population lives within the watershed of Lake Ontario.
Major cities (over 100,000 people) along Lake Ontario include Toronto [photo below], Mississauga, Hamilton, Burlington, Kingston and Whitby on the Canadian side, and Rochester, New York on the US side.
Like the other Great Lakes, Lake Ontario used to have an important commercial fishery. It has been largely destroyed, mostly by over-fishing and also by water pollution and invasive species. Today only recreational fishery activities exist.
Lake Ontario is host to a number of migratory birds. Swans, loons, ducks, geese, grebes and other water fowl are among the wildlife that inhabit Lake Ontario. Birds of prey such as hawks and eagles are also common in the area.
Lake Ontario has a “seiche”, a natural rhythmic motion as water sloshes back and forth every 11 minutes. The seiche effect normally is only about 2 centimeters (3⁄4 inches) but can be greatly amplified by Earth movement, winds, and atmospheric pressure changes.
Because of the lake’s depth and the warm weather that comes in from the southwest, Lake Ontario rarely freezes over; But an ice sheet covering between 10% and 90% of the lake area typically develops, depending on the severity of the winter. Lake Ontario has completely frozen over on five recorded occasions: from about January 20 to about March 20, 1830; in 1874; in 1893; in 1912; and in February 1934.
Ice glaciers melting at the end of the latest Ice Age were responsible for the formation of Lake Ontario and all of the other Great Lakes.
In the Wyandot (Huron) language, ontarío means “Lake of Shining Waters”.
Iroquois and Huron First Nations lived on the lake for thousands of years before Europeans arrived.
The first documented European to reach the lake was Étienne Brûlé in 1615.
Ontario, Canada’s most populous province, was named after the lake, and not vice versa.
As of 2015, about 50 people have successfully swum across the lake. The first person who accomplished the feat was Marilyn Bell, who did it in 1954 at the age of 16.
In 1804, a Canadian warship, His Majesty’s Ship Speedy, sank in Lake Ontario. In 1990, wreck hunter Ed Burtt manage to find it. Only, he isn’t allowed to recover any artifacts until a government-approved site to exhibit them is found. He’s still waiting.
A lake on Saturn’s moon Titan is named after Lake Ontario. It’s called “Ontario Lacus.”
Babe Ruth hit his first major league home run at Hanlan’s Point Stadium in Toronto. It landed in Lake Ontario and is believed to still be there.