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Sight of the fjord

Characteristics - Saguenay : An exceptional fjord!

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Formation
Characteristics
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Musée du Fjord

Graphic Graphic
Transverse profile of the fjord of Saguenay
Longitudinal section of the fjord of Saguenay
Rock face

A unique fjord : the Saguenay fjord is the southernmost of the province of Quebec. Indeed, we have a tendency to believe that all fjords are located either at high latitudes or only in Scandinavia, in South America, in New Zealand, in Iceland or in Scotland.

Shape : a fjord is a valley shaped by the passage of one or many glaciers which dug deep into itsbed giving it the shape of a glacial trough, a "U" shaped valley with an abrupt and imposing rock face.

Contact with the sea : fjords communicate with the sea at one extremity and receive an input of fresh water from the other, mixing together sea and fresh waters.

The presence of a rocky ridge at its mouth : fjords generally have a rocky ridge at their mouth or a transverse glacial rock bar made out of more resistant moraine rocks and debris that were dragged by the glaciers. The Saguenay's rocky ridge advances up to 4 kilometres in front of its mouth and reveals the presence of a 278-meter trench a little upriver from Tadoussac.

Water stratification : fjords are characterised by a very marked water stratification. On the surface, a rapid change, according to depth, occurs in the salinity, temperature and in the density of the water. This phenomenon creates a layer called the "thermo halocline" following the superimposition of the relatively warm fresh water from the incoming drainage basin onto a body of very cold and salted water at the bottom.

The presence of hanging valleys : they are valleys perpendicular to the fjord and located at a relatively higher altitude. These valleys use to hold a glacial tongue.

Its dimensions : the fjord spreads well over a hundred kilometres, which makes it one of the longest fjords in the world. Its width varies from 1 to 3,5 kilometres. It is well entrenched in the Laurentian's rocky massif. It is lined by very steep rock faces reaching average heights of 150 metres and some with altitudes going well over 400 meters like the Capes Trinité (411 m) and Éternité (457m).

Its bathimetry : one of the main characteristics of the fjord's bed is its highly contrasted bathimetry. As a matter of fact, there is a succession of three deep basins each separated by rocky elevations. Between Sainte-Rose-du Nord and l'Anse-Saint-Jean, their is a depth of 278 metres, which is around 170 metres higher than the St. Lawrence sea bed on each side of l'Île Rouge. In front of the St. Louis island, the bed plunges back down to 180 metres, comes back up in front of Bay Sainte-Marguerite to then reach depths of 278 metres again before reaching the mouth of the fjord.

Sedimentary accumulations : Results of recent studies reveal astounding figures in regards to the real depth of the fjord. Indeed they teach us that the sedimentary accumulations on the bed of the Saguenay can reach, in certain areas, over 1 400 metres, which is almost five times its present maximum depth. Between Saint-Fulgence and Bay Sainte-Marguerite, observations show an accumulation of 400 metres of which certain areas have been noted being form 600 to 800 metres thick. Once passed Bay Sainte-Marguerite, layers of Quaternary sediments reaching depths of 1000 to 1400 metres were detected. This would mean that the real depth of this fjord could reach over 2000 meters, taking in consideration the present relief over sea level.

Its main tributary : the Saguenay is a north shore affluent of the St. Lawrence. It is Quebec's fourth most important hydrographic basin and the second in importance as far as the volume of water it drains into the St. Lawrence River valley. Its total length is 160 kilometres, from its source in the Grande-Décharge and Petite-Décharge rivers, which are drainage outlets of the Lac Saint-Jean. It joins the St. Lawrence estuary around 200 kilometres north east of Quebec City. The outpour of water covers 88 000 km2, its yearly discharge is of 1300 m3/s, and can reach 3000 m3/s.

Due to certain singularities, the Saguenay is part river, part fjord. The river section spreads from the city of Alma to Saint-Fulgence. Henceforth, it is a long hydroelectric reservoir taking its source in the Lac-Saint-Jean and whose distance is delimited between the Lac-Saint-Jean drainage basin and the Shipshaw dam.

The mouth of the Chicoutimi river, whose Montagnais name means, "Where deep waters end", has always served as the marker to the end of the Saguenay's navigable waterway, either for simple canoes, large vessels or modern cruise ships.

Its main tributaries : the main tributaries that are the Éternité, Saint-Jean and Sainte-Marguerite rivers, occupy asymmetric, deep and very oblique valleys in regards to the fjord. Their forms are the result of different erosions, which occurred on the two shorelines of this valley following the transverse movement of the "stream" of ice that deepened the fjord's bed.

The Baie des Ha ! Ha ! : The Baie des Ha ! Ha ! is one of the elements of the fjord that cannot be ignored. Upstream, its divided in two sections, giving birth to the bay, northerly bound, and to the Northern arm, which is north easterly bound. The Northern arm leads to the Saguenay River and to the Chicoutimi district. Twenty kilometres long, the Baie des Ha ! Ha ! has all the same oceanographic characteristics as the fjord, with salted and cold waters (except for the surface layer) and contributes to influence the tides of the St. Lawrence estuary.

Blue Nose in Baie des Ha! Ha!
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