Lake Admiralty facts for kids

Quick facts for kids Lake Admiralty
Lake Admiralty Location in Great Lakes Show map of Great Lakes Lake Admiralty Location in New York Show map of New York Lake Admiralty Location in Ontario Show map of Ontario
Location	North America
Group	Great Lakes
Coordinates	43°34′55″N 77°19′12″W / 43.582°N 77.32°W / 43.582; -77.32
Lake type	former lake
Etymology	Admiralty
Primary inflows	Laurentide Ice Sheet
Primary outflows	Mohawk River to the Hudson River
Basin countries	Canada United States
First flooded	12,000 years before present
Max. length	241 mi (388 km)
Max. width	57 mi (92 km)
Residence time	7300 years in existence
Surface elevation	178 ft (54 m)

Admiralty Lake was a huge lake that existed a very long time ago. It was a proglacial lake, which means it formed from the melting ice of a giant glacier. This ancient lake filled the area where Lake Ontario is today.

What Was Lake Admiralty?

Lake Admiralty was a temporary lake that formed about 12,000 years ago. It existed in the basin, or natural bowl, that now holds Lake Ontario. This lake was created by the melting of the massive Laurentide Ice Sheet. This ice sheet was a huge glacier that covered much of North America.

How Lake Admiralty Was Different

The shoreline of Lake Admiralty was about 20 metres (66 ft) lower than Lake Ontario's current shoreline. This might seem strange, but it's because of how the land and ice changed over thousands of years.

The Story of Glacial Lakes

Before Lake Admiralty, there was an even older and larger lake called Glacial Lake Iroquois. Lake Iroquois had a much higher shoreline than Lake Ontario. This was because a part of the huge Laurentian Glacier blocked the valley of the St. Lawrence River. This blockage made the water level in Lake Iroquois much higher.

How the Lakes Drained

Lake Iroquois used to drain its water over the Niagara Escarpment. This is a long, steep cliff that runs across parts of North America. The water then flowed down the Mohawk River. From there, it continued into the Hudson River.

The Land Rises

As the giant glacier slowly melted and moved back, it became lighter. The weight of the ice had pushed the land down. When the ice retreated, the land slowly started to rise again. This process is called "rebounding."

The area around the Thousand Islands in the St. Lawrence River also rebounded. As this land rose, it changed how the water flowed. Eventually, the lake filled to its current level, becoming what we know today as Lake Ontario.