When North America was part of Pangea, the Cape Verde hot spot was under the Great Lakes region and was important for its creation due to the upwelling of hot material from the mantle.
A new paper published in the journal Geophysical Research Letters reveals that the North American Great Lakes owe their existence to a long-extinct hot spot beneath the supercontinent Pangea, ca. 300 million years.
O Cape Verde hot spotstill active under the island nation in the central Atlantic, played a key role in the formation of the region that would eventually host the lakes.
Hot spots are outcrops of hot mantle material terrestrial conditions that can significantly alter the crust. These phenomena are known to create volcanic features such as the Hawaiian Islands or Yellowstone National Park.
No case for two Great Lakes, or Cape Verde hotspot warmed and stretched the crust tens of millions of years ago, creating a low-altitude topography. During the last ice age, glaciers carved this depression and their meltwater filled the basins to form the Great Lakes, which currently contain 21% of the planet’s freshwater.
“It was the hot spot that left the first mark,” explained Aibing Li, a seismologist at the University of Houston and co-author of the study.
By examining seismic wave patterns in the crust beneath the lakes, researchers identified a phenomenon called “anisotropia radial”, which indicates a deformation in the lithosphere, explains .
Initially, this anomaly puzzled scientists, but a reconstruction of the movements of the tectonic plates clarified the situation — the Cape Verde hot spot was located at times directly underneath from the Great Lakes region, during the period when North America was part of Pangea.
Between 300 million and 225 million years ago, the hot spot was located beneath the area now occupied by Lake Superior. As the continent moved, the hot spot migrated beneath lakes Huron and Eriewest-central New York and northern Virginia, eventually moving offshore about 170 million years ago.
This discovery highlights the profound influence of mantle dynamics on surface geology. The researchers are now expanding their model to include the western Great Lakes region and investigating whether other large inland lakes may also be linked to ancient hot spots.
