The 1663 Charlevoix earthquake occurred on February 5, 1663 in the Canadian province of Quebec, and was assessed to have a moment magnitude of between 7.3 and 7.9. The earthquake occurred at 5:30 p.m. local time and was estimated to have a maximum perceived intensity of X (Intense) on the Mercalli intensity scale. The main shock epicentre is suggested to have occurred along the Saint Lawrence River,[2] between the mouth of the Malbaie River on the north and the mouth of the Ouelle River on the south. A large portion of eastern North America felt the effects.[2] Landslides and underwater sediment slumps were a primary characteristic of the event with much of the destruction occurring near the epicentral region of the St. Lawrence estuary and also in the area of the Saguenay Graben.