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 Airlines (Canada) Great Lakes Airlines (Canada) Great Lakes Airlines was a regional airline in Canada. It was formed in 1958 in Sarnia, Ontario by John Blunt and by 1983 became Air Ontario Ltd. In June 1987 Air Ontario Ltd. merged with Austin Airways to form Air Ontario Inc. which in turn subsequently operated Air Canada Connector code sharing passenger flights on behalf of Air Canada with Convair 580 and de Havilland Canada DHC-8 Dash 8 series 100 and 300 turboprops. Air Ontario also operated Fokker F28 Fellowship jets at one point. Aircraft in service with Great Lakes during the 1970s, being Convair