Coasts. – Two aspects of the coasts are more characteristic: the branched system of fjords and the fringe of numerous islands in which the configuration of the mainland continues. The fjords, which often extend into the submarine shoe, are submerged valleys, carved out by glaciers in the Tertiary valleys and often have a great depth due to rejuvenation of the relief at the end of the Tertiary. The greatest depth is generally found inside and not at the mouth, which is occupied by a threshold or a series of several thresholds.
According to topschoolsintheusa, the fringe of islands, called skjærgård, is made up of about 150,000 islets and rocks and a few larger islands. They are but the outer part of a platform or bank of rocks which borders, for a large part of its length, the west coast on a width from iat 12 km., from whose inner edge, for the most part, a steep slope rises to the highest lands. This shelf forms an elevated part of the continental shelf and was probably formed by marine erosion during phases of slow submersion in interglacial periods or before the glacial period, during which this terrace resulting from abrasion was smoothed by glaciers and cut into islands. from the ice currents. The Arctic coast lacks islands from the North Cape to Varanger. The fjords of this coast are relatively wide and shallow inlets, such as Varanger, Tana and Porsanger.
Between the North Cape and Stavanger the skjærgård is fully developed, barring a few interruptions. In S. of Lyngenfjord the large groups of the islands of Vesterålen and Lofoten are separated from the mainland by the Vestfjord. The Saltenfjord is famous for the powerful rapids produced by the tides. The Trondheimsfjord is surrounded by fertile clay plains below the ancient sea limit. In S. di Trondheim the most famous fjords meet for the beauty of the landscape: Romsdalsfiord, Storfjord, Nordjord and Sognefjord which reach Jostedalsbre respectively on the northern and southern sides. The Sognefjord is also the deepest (1244m, but only 250m at the mouth) and the longest, penetrating the mainland for about 175km. The Hardangerfjord is located south of Bergen; the Stavangerfjord (with the Lysefjord) is the southernmost , south of it lie the vast Norwegian coastal plains of Jaeren and Lista. Going beyond these plains always towards the south, the skjærgård begins again, however it is less developed than the northern one.
The Oslo fiord has its own geological origin, having been formed by several dislocations, the largest of which is easily distinguished along the eastern shore where the rock rises to a considerable height a few meters away from the islets formed of Paleozoic schists.
Climate. – The west coast has a milder and more humid climate than that of the eastern and north-eastern regions. Norway enjoys very high average temperatures compared to latitudes: thermal anomalies reach 24 ° in Lofoten (15 ° in Lindesnes) due to the influence of the ocean and the Gulf Stream, whose tepid surface waters penetrate the fjords and in the straits, keeping them free from ice. The isotherms of July and also those of January tend to follow the coast, along which summer temperatures are relatively low, with averages in July of 13 ° -14 ° (January average: 0 °).
The annual excursion is much stronger in the interior, where the averages for January and July are respectively −8 ° to −10 ° and + 17 °. The Glomma valley is very cold; Tynset has an excursion of 25 ° (Bergen, 13 °). But the coldest place in all of Norway is in Finnmarken, at 69 ° lat. Norway: here the January average is – 16 ° and the absolute minimum −51 °. Bergenha has 73 days of frost per year, Oslo has 141. Precipitation is more abundant on the west coast, with a zone of maximum precipitation, located at a certain distance from the coast itself. The average rainfall on the coast is 2000 mm. which rise to 3000 in the vicinity of Florø. Even larger quantities can be found a little higher up on the sides of the mountains. The mountain valleys sheltered from the rain, to the East. of the mountains of southern Norway, have the minimum annual rainfall which falls to 254 mm. Averages below 400 mm. they are also found in Finnmark. The snow limit, in addition to latitude, depends on the amount of precipitation, exposure to the sun and especially to the wind. Attempts to clarify this limit have yielded figures ranging from 100 m. in the Lofoten islands at 1250 m. to Norway of Bergen. Fog is very frequent on the southwestern coasts. The winds of SW. they prevail, especially in winter. In the summer, an area of low pressure forms in inland regions. Storms are common on the west coast. North of 66 ° 5 ‘lat. Norway the sun disappears entirely for part of the winter and remains invisible in the North Cape for two and a half months. The summer months enjoy continuous sunshine, day and night.
Rivers. – The river systems of Norway have characters of immaturity; lakes abound and waterfalls are frequent. The numerous lakes generally correspond to the points of greatest depression produced in the bottom of the valleys by glacial erosion. As a rule, they are long, often very deep, but of little surface; for the most part they resemble simple expansions in the width of rivers. The deepest lake in Europe is the Hornindalsvatn, near the Nordfjord (52 msm) with the maximum depth of 514 m. A large number of lakes have their beds below sea level and many of the lakes that are at a higher level also have great depth, eg. the Bygdin in Jotunheim. The largest of the Norwegian lakes is Mjøsa, which has an area of 359 sq km, a maximum depth of 450 m. and is located at 124 ms m. The total area occupied by the lakes is 14,087 square kilometers, equal to 4.4% of the surface of the whole of Norway.
The countless rapids and waterfalls make water transport very difficult. Even the major rivers can only be used for very short stretches from the mouth, except where locks have been built. But rivers are very useful for transporting wood in spring, when the thaw produces violent floods. The falls are also used for hydroelectric plants.
The major rivers of Norway are located on the eastern side of the mountain range. Among them, the main one is the Glomma, which originates at about 762 meters above sea level and has a course of about 600 km. with a basin of 20 thousand sq. km. It emits the richest timber districts (Østerdalen) which have a total area of 15,000 sq km. The Gudbrandsdalslågen river (with a basin of about 17,000 sq. Km.) Leaves the Lesiaskogvatn lake (625 msm) located exactly on the watershed, since it also gives rise to the river that crosses the Romsdal. The Dramselva is the lower course of a river system which has a considerable basin. The Numedalslagen and the rivers of the Telemark drain the waters of the Hardangervidda. Southern Norway is crossed by numerous rivers which flow parallel to each other in the Norway-S direction. The shorter and faster rivers of the west coast are famous for their large waterfalls (Vøringfoss, 163 m.; Vettisfoss, 260 m.; the Seven Sisters). The Namsen, Norway of the Trondheimsfjord, runs through the northernmost lumber districts. The rivers that flow into the Arctic Ocean are greater; the Altenelv and the Tanaelv have gentler slopes, but they do not have lakes that act as regulators during flood periods (for more information on climate and hydrography see.scandinavia).
