The Superior Shoal is a geologic

shoal In oceanography, geomorphology, and geoscience, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material and rises from the bed of a body of water to near the surface. It ...

of approximately located north of

Copper Harbor, Michigan Copper Harbor is an Unincorporated area, unincorporated community and census-designated place (CDP) located in Keweenaw County, Michigan, Keweenaw County in the U.S. state of Michigan. It is located within Grant Township, Keweenaw County, Michigan ...

in the middle of

Lake Superior Lake Superior in central North America is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. and the third-largest by volume, holding 10% of the world's surface fresh wa ...

, the highest point of which lies only below the lake's surface. The shoal is a hump of Keweenawan

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

ic lava flows with ophitic interiors and amygdaloidal tops in an otherwise deep part of the lake, and though fishermen had known of its existence for generations it was only officially charted in 1929 by the

United States Lake Survey The United States Lake Survey (USLS) was a hydrographic survey for the Great Lakes, New York Barge Canal, Lake Champlain and the Boundary Waters of the Canada–United States border between Minnesota and Ontario. The Survey's activities began on ...

. It has been theorized that the World War I French minesweepers ''Inkerman'' and ''Cerisoles'', which disappeared during their maiden voyage on Lake Superior in mid-November 1918, may have run aground on this shoal and some have theorized that it may have been to blame for both the disappearance of the " Flying Dutchman of the Great Lakes" on November 21, 1902 and the sinking of the "Titanic of the Great Lakes" on November 10, 1975 (the '' SS Bannockburn'' and SS ''Edmund Fitzgerald'', respectively). It is one of the known off-shore spawning and foraging habitats for the juvenile lean lake trout.

Geology

The shoal consists of four geologic ridges: the north ridge, the central ridge, the halfway ridge, and the south ridge. The north ridge is a subtle but distinct rise across the northern portion of the shoal; the central ridge consists of a few high peaks in the eastern-center of the shoal; the halfway ridge is the largest ridge and stretches in an arc from east to west across the entire feature; the south ridge is made up of two associated basalt rises on the southern edge of the formation. The Isle Royale Fault creates a gorge between the north ridge and the other three ridges. A different shoal with the same name is located just off Delf Island in

Georgian Bay Georgian Bay (french: Baie Georgienne) is a large bay of Lake Huron, in the Laurentia bioregion. It is located entirely within the borders of Ontario, Canada. The main body of the bay lies east of the Bruce Peninsula and Manitoulin Island. To ...

east of

Lake Huron Lake Huron ( ) is one of the five Great Lakes of North America. Hydrology, Hydrologically, it comprises the easterly portion of Lake Michigan–Huron, having the same surface elevation as Lake Michigan, to which it is connected by the , Strait ...

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...

References

{{Reflist Lake Superior