Category: Earth Science
Lake Superior is the largest of the Great Lakes. It has both the largest surface area and volume. It has the highest sea level elevation of the Great Lakes. It is the deepest of the Great Lakes with an average depth of 489 feet. The maximum depth is 1,333 feet, also called 222 fathoms. That spot is west of Marquette Michigan.
Lake Superior is also thought to be the oldest of the Great Lakes. It is the largest freshwater lake in the world by surface area. It the third largest freshwater lake by volume (first place goes to Lake Baikal in Russia), but it is the largest freshwater lake in North America. Lake Superior isn’t the deepest lake in Norht America; that title goes to Crater Lake.
Lake Superior is so large and rough that ships traversing the lake need to be ocean-worthy. The largest recorded waves on the lake were 51 feet high near Whitefish Bay. The lake naturally rises and falls by a foot due to a phenomena called seiche. This isn’t due to tidal effects but wind pressure.
The Lake Superior port of Duluth is the most inland port in the world. It is located on the St. Lawrence Seaway.
Lake Superior is the cleanest of the Great Lakes and has the best visibility, with visitors able to look down as far as eight feet.
What Is In a Name?
The American spelling for the lake is Lake Superior. The French name is Lac Superieur. The Ojibwe tribe called the lake gichigami, which meant “great sea”. It was also called Ojibwe Gichigami, the Objibwe’s Great Sea.
The lake is divided by the U.S.-Canadian border. The northern side of the lake is bordered by Ontario. On the American side, it is bordered by Minnesota, Wisconsin and Michigan.
Lake Superior covers an area of 31,700 square miles. It is 160 miles wide.
It has a volume of 2,903 cubic miles. Its shoreline is around 3000 miles.
Lake Superior is fed by over 200 rivers, the largest of which include the Nipigon River and St. Louis River. It drains only to Lake Huron.
Lake Superior is home to a number of Islands. The largest island is Isle Royale. Isle Royale has several lakes of its own.
Lake Superior and the other Great Lakes moderate the climate in their area. They keep summers cooler and winters warmer than the continental climate fifty miles or so inland. They generate massive amounts of snow on the southern side of the lake, due to the prevailing winds that push humid air in that direction. This creates fog in the late spring through the fall.
Lake Superior rarely freezes over. It did freeze completely over in 1997. It generally freezes between 40% and 95%.
Lake Superior is very cold with an average water temperature of 40 F or 4 C.
The lake is stormiest in October and November.
The greatest benefit of Lake Superior is the cheap water travel is provides to major manufacturers around the lake. The largest port on the Lake is Duluth Michigan. Around a thousand vessels visit that port per year. The Soo Locks were put in place to allow ships from Lake Superior to travel to Lake Huron.
The flushing rate refers to how quickly all the water in the lake is changed out, relative to drainage into the basin and flows out to Lake Nicolete and Lake Huron via the St. Mary’s River. The flushing rate for Lake Superior is 400 to 500 years. The average detention rate for a drop of water in the lake is estimated to be 191 years. These values are much lower for the other Great Lakes.
Lake Superior has been the site of about 350 shipwrecks.
The Great Lakes contain 20% of the world’s readily available fresh water (this doesn’t include what is locked up in the ice caps). Of that fresh water in the Great Lakes, half of it is in Lake Superior.