Mjøsa

Mjøsa
Aerial view
Mjøsa Location of the lake Mjøsa Mjøsa (Akershus) Mjøsa Mjøsa (Norway)
Location	InnlandetandAkershus
Coordinates	60°40′N11°00′E
Type	glacial fjord lake
Primary inflows	Gudbrandsdalslågen,Brumunda, Flagstadelva, Hunnselva, Lenaelva, Mesna, Moelva, Stokkeelva, Svartelva, Vikselva and Vismunda
Primary outflows	Vorma
Catchment area	16,563.89 km2(6,395.35 sq mi)
Basincountries	Norway
Max. length	117 km (73 mi)
Max. width	9 km (5.6 mi)
Surface area	369.48 km2(142.66 sq mi)
Average depth	150–153 m (492–502 ft)
Max. depth	453 m (1,486 ft)
Water volume	56.24 km3(13.49 cu mi)
Shore length1	341.11 km (211.96 mi)
Surface elevation	119–123 m (390–404 ft)
Islands	Helgøya
Settlements	Hamar,Gjøvik,Lillehammer
References	NVE
1Shore length isnot a well-defined measure.

MjøsaisNorway's largest lake, as well as one of thedeepest lakesin Norway and inEurope.It is the fourth-deepest lake in Norway.It is located in the southern part of Norway, about 100 kilometres (62 mi) north of the city ofOslo.Its maintributaryis the riverGudbrandsdalslågenflowing in from the north; the onlydistributaryis the riverVormain the south. Inflows would theoretically need 5.6 years to fill the lake. With an average depth of about 150 metres (490 ft), most of the lake's volume is under sea level. The average outflow of the lake (measured from 1931–1982) is 316cubic metres per second(11,200cu ft/s) which is about 9,959,000,000cubic metresperyear(1.1145×10¹⁰cu ft/Ms).Mjøsa contains about 56.2 km³(13.5 cu mi) of water compared to the 14.8 km³(3.6 cu mi) in the lakeRøssvatnet,the second largest lake by volume in Norway.

With a surface elevation of about 121 metres (397 ft), the depth of Mjøsa means that the deepest part of the basin is located approximately 332 metres (1,089 ft) below sea level. This is lower than the deepest point of the sea inlet ofKattegatand the lower than the vast majority ofSkagerrakoff Norway's south coast. Mjøsa retains a larger average depth than both theNorth SeaandBaltic Searespectively.

Thomas Robert Malthustraveled through Norway in 1799 and his diaries from the trip includes a description of Mjøsa. Malthus wrote that Mjøsa appears as both lake and river because the shores are defined by mountains and where the valley becomes wider the water fills the space. Below Minde (Minnesund) the lake only appears like a river and is calledVormaon the map, according to Malthus.

Location

Map with citiesLillehammer(North),Gjøvik(West), andHamar(East)

From its southernmost point at Minnesund inEidsvollto its northernmost point inLillehammerit is 117 kilometres (73 mi) long.At its widest, near the town ofHamar,it is 9 kilometres (5.6 mi) wide.It is 369 square kilometres (142 sq mi)in area and its volume is estimated at 56 km³(13 cu mi); normally its surface is about 121–123 m (397–404 ft) above sea level, and its greatest depth is 453 m (1,486 ft).Its total coastline is estimated at 341 km (212 mi), of which 30% is built up. Dams built on the distributary of Vorma in 1858, 1911, 1947, and 1965 raised the level by approximately 3.6 m (12 ft) in total. During the 19th and 20th centuries, there have been 20 floods recorded that added at least 7 m (23 ft) to the level of the lake which caused flooding. Several of these floods inundated the city ofHamar.

The towns ofHamar,Gjøvik,andLillehammerwere founded along the shores of the lake. Before the construction of railways past the lake, it was an important transport route. Today, aside from minor leisure boating and the steamshipSkibladner,there is no water traffic on the lake. Most of its shores are dominated by rolling agricultural areas, among them some of the most fertile grainlands in Norway. The main train line, theDovre LinebetweenOsloandTrondheim,goes along its eastern shore, making stops atHamar StationandLillehammer Station.From the south, theEuropean route E6highway runs along the eastern shore of the lake until theMjøsa BridgeconnectsMoelvon the east withBirion the west.

Mjøskastellet

Drawing of Mjøstkastellet as imagined by Peter Andreas Blix

The largest and only island in the lake isHelgøya.Except for Helgøya, Mjøsa only contains small islets. The most interesting of these is Steinsholmen, which holds the ruins of Mjøskastellet, amedievalcitadeldating from the 13th century. Established by KingHaakon IV of Norway,it was first mentioned historically in a letter dated 1234.Peter Andreas Blixdocumented the site and made drawings in 1897.Hedmark Museumhas a future archaeological plan for the site.

Fish

Lake Mjøsa has 20 species of fish. Among the most common arepike,European perch,common roach,greyling,and the hundertrout, abrown troutwhich can reach a weight more than 20 kilograms (44 lb). Another common species is theEuropean smelt,which is the most importantbait fishfor the predators. Historically, the most economically significant species is thelågsild(European cisco).

Source of drinking water

Several municipal and urban areas use the lake as their source of drinking water.

• Hamar/Ottestad– Hias IKS has responsibility for thewaterworksandwaste water treatment plantsinHamar Municipality,Stange Municipality,andLøten Municipality.
• Lillehammer– Operates waterworks at Korgen. Contracts have been signed for a new flood-proof waterworks to be built in Hovemoen.
• Gjøvik– WWTP run from Rambekk Renseanlegg
• Østre Toten– Kapp / Skreia
• Brumunddal– Biri / Moelv

Name

The lake is named "Mjøsa" (Old Norse:Mjǫrs/Proto-Norse*Merso) and this name must be very old. The meaning is possibly "the bright/shiny one". This is based on the theory that the first element*mer-is related to the English wordmerewhich means "clear" or "bright" and-sois asuffix.

• 
  The lake seen from the harbor inHamar
• 
  The landmark Geiteryggen looking south from Hamar
• 
  Mjøsa from Hamar
• 
  SteamboatSkibladneron the lake of Mjøsa
• 
  Steinholmen on lake Mjøsa

Events

From 1932 to 1934,ice racingwas held on the lake's northern reaches near Lillehammer. Warmer winters had forced race organisers to move racing fromGjersjøennearOslo.TheNorwegian Grand Prixwas held there in 1934. The race was won by Swedish driverPer-Viktor Widengrenin anAlfa Romeo 8Cbut poor attendance saw the Grand Prix move back to the Oslo region in 1935.

In 1975, the14th World Scout Jamboreewas held on its shores. More than 17,000Scoutsfrom 91 countries took part.

In 1995, a Canadian historic aircraft organization namedHalifax 57 Rescuerecovered a mostly intactHandley Page Halifaxbomberfrom it, which was previously discovered in 1991 to be resting at a depth of 750 feet (228.6 m). The aircraft, NA337, was shot down at 0131 hours on 24 April 1945 while returning from a supply mission and crashed shortly after. It was later restored extensively to its original state (albeit non – flying) and is now one of only three remaining examples of the type anywhere in the world.

Culture projects

The inter-county public art collaboration project,Det Var Jo Ingen Horizont Deris a model for inter-organizational cooperation and collaboration between local municipalities and counties. It is a public "land-art" project that was supported by theOppland County MunicipalityandHedmark County Municipalityas well as local municipalities ofEidsvoll,Gjøvik,Hamar,Lillehammer,Ringsaker,Stange,andØstre Toten.These communities all share shoreline with Mjøsa.Det Var Jo Ingen Horizont Der,is an environmental art collaboration including the works of 12 artists' sculptural and multimedia environmental artworks installed at 20 geographic places on and around the shores of Mjøsa. The project is documented in a book and it was part of an exhibition at the Mjøsmuseet (museum) in 2019.

See also

• Toftes Gave

External links

• Mjøskastellet(DigitaltMuseum)