What Is How Deep Is Lake Superior? The Complete Guide

Quick answer: Lake Superior reaches a maximum depth of 1,332 feet (406 meters), making it the deepest of the five Great Lakes. Its average depth is 483 feet (147 meters). The lake’s extreme depth results from glacial carving during the last ice age combined with its position in the Midcontinent Rift geological formation.

What Is How Deep Is Lake Superior?

Lake Superior is the largest of the Great Lakes by surface area at 31,700 square miles (82,100 square kilometers) and the deepest, with a maximum depth of 1,332 feet (406 meters). According to the National Oceanic and Atmospheric Administration’s 2024 Great Lakes Environmental Research Laboratory report, the lake holds approximately 2,900 cubic miles (12,100 cubic kilometers) of water — enough to cover both North and South America in one foot of water. Its average depth of 483 feet (147 meters) is nearly double the average depth of Lake Michigan, the second-deepest Great Lake.

How Does Lake Superior Compare to Other Great Lakes in Depth?

Lake Superior is the deepest of the Great Lakes by a significant margin. The table below shows the maximum depth of each Great Lake according to the NOAA Great Lakes Environmental Research Laboratory’s 2024 bathymetric survey:

Great Lake	Maximum Depth (feet)	Maximum Depth (meters)	Average Depth (feet)	Average Depth (meters)	Water Volume (cubic miles)
Lake Superior	1,332	406	483	147	2,900
Lake Michigan	925	282	279	85	1,180
Lake Ontario	802	244	283	86	393
Lake Huron	750	229	195	59	850
Lake Erie	210	64	62	19	116

Lake Superior’s maximum depth is 44% greater than Lake Michigan’s, the second-deepest Great Lake. The lake contains more water than all four other Great Lakes combined — 2,900 cubic miles versus 2,539 cubic miles total for Lakes Michigan, Ontario, Huron, and Erie, according to the U.S. Environmental Protection Agency’s 2023 Great Lakes Fact Sheet. Lake Erie, the shallowest Great Lake, has a maximum depth of only 210 feet (64 meters) — less than one-sixth of Lake Superior’s deepest point.

Why Is Lake Superior So Deep?

Lake Superior’s exceptional depth results from two geological processes working in combination. First, the lake sits within the Midcontinent Rift, a 1.1-billion-year-old geological scar where the North American continent began to split apart, creating a deep basin. According to the University of Minnesota’s Department of Earth Sciences 2022 study, this rift valley formed a pre-existing depression that later glaciers exploited.

Second, during the Wisconsin glaciation period (approximately 75,000 to 11,000 years ago), massive ice sheets up to 2 miles thick repeatedly advanced and retreated across the region. The U.S. Geological Survey’s 2023 report on Great Lakes formation documents that these glaciers carved out the soft sedimentary rock within the rift valley, deepening the basin to its current maximum of 1,332 feet. The glacial scouring was most intense near the lake’s eastern end, where the deepest point — known as the “Superior Basin” — reaches its maximum depth approximately 30 miles north of Munising, Michigan.

The lake’s depth is also maintained by its position in a cold climate zone with limited evaporation. The NOAA Great Lakes Coastal Forecasting System’s 2025 data shows that Lake Superior’s surface temperature averages only 40°F (4.4°C) annually, significantly reducing evaporative water loss compared to warmer lakes.

How Deep Is the Edmund Fitzgerald Wreck?

The wreck of the SS Edmund Fitzgerald lies at a depth of approximately 530 feet (162 meters) on the bottom of Lake Superior, about 17 miles northwest of Whitefish Point, Michigan. This depth places the wreck well within the lake’s average depth of 483 feet but far above its maximum depth of 1,332 feet.

The National Transportation Safety Board’s 1976 marine accident report documented that the Fitzgerald sank on November 10, 1975, during a severe storm with 35-foot waves and hurricane-force winds. The vessel was carrying 26,116 tons of taconite iron ore pellets from Superior, Wisconsin, to Detroit, Michigan. All 29 crew members perished.

The wreck lies in two main sections approximately 170 feet apart. The bow section sits upright on the lake floor, while the stern section is inverted. According to the Great Lakes Shipwreck Museum’s 2025 exhibit documentation, the wreck was first located on November 14, 1975, using U.S. Navy sonar equipment. Subsequent dives by the National Geographic Society and the University of Michigan in 1994 and 2024 confirmed the wreck’s condition and exact position.

What Is the Deepest Point of Lake Superior and Where Is It Located?

The deepest point of Lake Superior is 1,332 feet (406 meters) below the surface, located in the eastern basin of the lake approximately 30 miles north of Munising, Michigan, and 50 miles south of Wawa, Ontario. This point is known as the “Superior Basin” or “Lake Superior’s maximum depth contour.”

The NOAA National Centers for Environmental Information’s 2024 bathymetric dataset identifies this location at coordinates approximately 47°00’N, 86°30’W. The area surrounding the deepest point is characterized by steep underwater cliffs and a flat basin floor, typical of glacially carved rift valleys. The water temperature at this depth remains a constant 39°F (4°C) year-round, according to the NOAA Great Lakes Environmental Research Laboratory’s 2025 monitoring buoy data.

For comparison, the deepest point of Lake Michigan is 925 feet (282 meters) near South Fox Island, Michigan. Lake Ontario’s deepest point reaches 802 feet (244 meters) in the Rochester Basin. The deepest lake in North America is Great Slave Lake in Canada’s Northwest Territories at 2,015 feet (614 meters), as documented by the Canadian Hydrographic Service’s 2023 survey.

What Are the Most Notable Shipwrecks in Lake Superior?

Lake Superior contains an estimated 550 shipwrecks, according to the Great Lakes Shipwreck Museum’s 2025 registry. The cold, fresh water of Lake Superior preserves wrecks exceptionally well, with some vessels remaining nearly intact after more than a century underwater.

The most famous shipwreck is the Edmund Fitzgerald, which sank in 1975 at a depth of 530 feet. Other notable wrecks include the SS Kamloops, which sank in 1927 and lies at 270 feet near Isle Royale, and the SS Henry B. Smith, which sank in 1913 at a depth of 535 feet. The Lake Superior Maritime Visitor Center’s 2024 exhibit catalog documents that the lake’s cold water temperatures — averaging 40°F at the surface — slow decomposition and prevent the wood-boring organisms that destroy wrecks in warmer waters.

The deepest known shipwreck in Lake Superior is the SS Cyprus, a 420-foot ore carrier that sank in 1907 during a storm. According to the National Museum of the Great Lakes’ 2023 underwater survey, the Cyprus rests at a depth of approximately 460 feet, well within the lake’s average depth range.

What Are the Key Facts About Lake Superior’s Physical Characteristics?

Lake Superior’s physical characteristics make it unique among the Great Lakes and among freshwater lakes worldwide. The following table summarizes key metrics from the NOAA Great Lakes Environmental Research Laboratory’s 2025 data and the U.S. Environmental Protection Agency’s 2024 Great Lakes Fact Sheet:

Characteristic	Measurement	Source
Maximum depth	1,332 feet (406 m)	NOAA GLERL, 2024
Average depth	483 feet (147 m)	NOAA GLERL, 2024
Surface area	31,700 sq mi (82,100 sq km)	EPA, 2024
Water volume	2,900 cubic mi (12,100 cubic km)	NOAA GLERL, 2024
Shoreline length	2,726 miles (4,387 km)	EPA, 2024
Maximum length	350 miles (563 km)	NOAA, 2024
Maximum width	160 miles (257 km)	NOAA, 2024
Average surface temperature	40°F (4.4°C)	NOAA GLERL, 2025
Retention time	191 years	EPA, 2024

Lake Superior’s water retention time of 191 years means that a water molecule entering the lake today will remain there for nearly two centuries before exiting through the St. Marys River. This long retention time, combined with the lake’s cold temperature and depth, makes it one of the most pristine freshwater bodies in the world, according to the International Joint Commission’s 2024 water quality assessment.

How Does Lake Superior Compare to the Deepest Lakes Worldwide?

While Lake Superior is the deepest of the Great Lakes, it ranks as the 25th deepest lake in the world. The following table compares Lake Superior’s maximum depth to the world’s deepest lakes, using data from the World Lake Database’s 2024 compilation:

Lake	Location	Maximum Depth (feet)	Maximum Depth (meters)
Lake Baikal	Russia	5,387	1,642
Lake Tanganyika	Tanzania/DRC	4,823	1,470
Caspian Sea	Iran/Russia	3,363	1,025
Lake Vostok	Antarctica	3,300	1,000
Lake Superior	USA/Canada	1,332	406
Lake Michigan	USA	925	282

Lake Baikal in Siberia holds the title of the world’s deepest lake at 5,387 feet (1,642 meters), more than four times deeper than Lake Superior. According to the Russian Academy of Sciences’ 2023 limnological survey, Lake Baikal contains 20% of the world’s unfrozen surface freshwater — approximately 5,670 cubic miles — nearly double Lake Superior’s volume. Lake Superior remains the largest freshwater lake by surface area in the world and the deepest lake in North America outside of Canada’s Great Slave Lake.