Þingvallavatn (Icelandic pronunciation: [ˈθiŋkˌvatlaˌvahtn̥]), anglicised as Thingvallavatn,[Note 1] is a rift valley lake in southwestern Iceland. With a surface of 84 km² it is the second largest natural lake in Iceland. Its greatest depth is 114 m. At the northern shore of the lake, at Þingvellir (after which the lake is named), the Alþingi, the national parliament, was founded in the year 930, and held its sessions there until 1799 and still as of today the name Alþingi Íslendinga is carried by the parliament of Iceland.

Fissures at the lake
LocationÞingvellir National Park
Coordinates64°11′N 21°09′W
Primary outflowsSog
Basin countriesIceland
Surface area84 km2 (32 sq mi)[1]
Average depth34 m (112 ft)[1]
Max. depth114 m (374 ft)[1]
Water volume2.856 km3 (0.685 cu mi)[1]
Residence time11 months[2]

The lake lies partially within Þingvellir National Park. The volcanic origin of the islands in the lake is clearly visible. The cracks and faults around it, of which the Almannagjá [ˈalˌmannaˌcauː] ravine is the largest, is where the Eurasian and North American tectonic plates meet. Silfra fissure is a popular scuba and snorkeling site. The only outflow from lake Þingvallavatn is the river Sog.

One of the noted features of the lake is the presence of four morphs of the Arctic charr.[3]

See also

Notes and references


  1. The spelling Pingvallavatn is wrong as the letter “p” should never be used to represent the letter “þ” (thorn).


  1. EÖÞ. "Vísindavefurinn: Hvað er Þingvallavatn djúpt?". Visindavefur.hi.is. Retrieved 2016-04-23.
  2. "Fróðleiksmoli: dvalartími vatns | Fróðleiksmolar | Veðurstofa Íslands" (in Icelandic). Vedur.is. Retrieved 2016-04-23.
  3. Malmquist, H. J., Snorrason, S. S., Skulason, S., Jonsson, B., Sandlund, O. T., & Jonasson, P. M. (1992). Diet differentiation in polymorphic Arctic charr in Thingvallavatn, Iceland. Journal of Animal Ecology, 21-35.