[3] 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.

The event occurred during the early European settlement of North America and some of the best recorded first hand accounts were from Catholic missionaries that were working in the area.

The main structures of the area are faults of the Saint Lawrence rift system that run parallel to the river, formed during the break-up of the supercontinent Rodinia in the late Neoproterozoic and early Paleozoic.

The relatively weak impact structure is interpreted to cause a perturbation of the regional stress field, affecting the stability of the rift faults.

[6] This level of damage is consistent with a modified Mercalli intensity of VI though this may have been because the early colonials had the capability of producing only relatively weak mortar.

In 1996 it was the site of the largest flood in 20th-century Canadian history, which led to the investigation of the fjord bottom using bathymetric data to determine slope stability.

[13][14] Some very detailed, though inconsistent, summaries were given by several Jesuits, most notably Jérôme Lalemant who provided relatively reserved written accounts of the strong effects of the earthquake back to his superiors in Europe.

[4] Lalemant was said to have been a disciplined priest with diverse experience and following his time in Canada was brought back to France to be posted the provincial superior of the Society of Jesus.

Father Simon seemed to not be of the same mind as the bulk of the devoted, saying "...the Earthquake was rather a Scheme of Divine Mercy than a scourge of Justice,— especially since, in so great a confusion of affairs and perturbations of the elements, no one lost life or fortune.