what type of water is in lake ontario
Lake Ontario Lake Ontario is the easternmost of the Great Lakes and the smallest in surface area (7,340 sq mi, 18,960 km2),[1] although it exceeds Lake Erie in volume (393 cu mi, 1,639 km3). It is the 14th largest lake in the world. When its islands are included, the lake has a shoreline that is 712 miles (1,146 km) long. As the last lake in the Great Lakes' hydrologic chain, Lake Ontario has the lowest mean surface elevation of the lakes at 243 feet (74 m)[2] above sea level; 326 feet (99 m) lower than its neighbor upstream. Its maximum length is 193 statute miles (311 kilometres; 168 nautical miles) and its maximum width is 53 statute miles (85 km; 46 nmi).[2] The lake's average depth is 47 fathoms 1 foot (283 ft; 86 m), with a maximum depth of 133 fathoms 4 feet (802 ft; 244 m).[2][3] The lake's primary source is the Niagara River, draining Lake Erie, with the St. Lawrence River serving as the outlet. The drainage basin covers 24,720 square miles (64,030 km2).[1][5] 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). These water level fluctuations are an integral part of lake ecology, and produce and maintain extensive wetlands.[6][7] The lake also has an important freshwater fishery, although it has been negatively affected by factors including over-fishing, water pollution and invasive species.[8]
Lake Erie Lake Erie was carved out by glacier ice,[1] and in its current form is less than 4,000 years old, which is a short span in geological terms. Before this, the land on which the lake now sits went through several complex stages. A large lowland basin formed over two million years ago as a result of an eastern flowing river that existed well before the Pleistocene ice ages. This ancient drainage system was destroyed by the first major glacier in the area, while it deepened and enlarged the lowland areas, allowing water to settle and form a lake. The glaciers were able to carve away more land on the eastern side of the lowland because the bedrock is made of shale which is softer than the carbonate rocks of dolomite and limestone on the western side. Thus, the eastern and central basins of the modern lake are much deeper than the western basin, which averages only 25 feet (7.6Â m) deep and is rich in nutrients and fish.[34] Lake Erie is the shallowest of the Great Lakes because the ice was relatively thin and lacked erosion power when it reached that far south, according to one view.