Great Lakes tectonic zone southern Ontario. Several earthquakes have been documented in Minnesota in the last 120 years, with at least six in the GLTZ. The epicenters show a clear relationship to tectonic features of the state; four epicenters lie along the Great Lakes tectonic zone. Depths are estimated at . The best-documented event occurred on July 9, 1975, near Morris, Minnesota, with a magnitude of 4.6, and a felt area of covering parts of four states. Wisconsin has had no earthquakes along the GLTZ, Michigan's Upper Peninsula has had four earthquakes in the vicinity of the GLTZ – Negaunee, Newberry and two in
Great Lakes Basin the Great Lakes Charter of 1985, the 2001 Charter Annex, and the Agreements of 2005. While not a part of the Great Lakes Basin, Quebec's position along the Saint Lawrence Seaway makes it a partner in water resource management with Ontario and the eight US states mentioned above. There are many nuclear power plants in the Great Lakes Basin. Twenty power plants on the Canadian side. The radioactive waste they produce and release like radioactive tritium have not been collectively combined to ascertain the total impact on the area. Great Lakes Basin The Great Lakes Basin consists of the Great