Lake Lappajärvi

Lake Lappajärvi

Lappajärvi is the largest lake near the lower right corner.
Location Lappajärvi, Finland
Coordinates 63°12′N 023°42′E / 63.200°N 23.700°E / 63.200; 23.700Coordinates: 63°12′N 023°42′E / 63.200°N 23.700°E / 63.200; 23.700
Type impact crater
Primary outflows Ähtävänjoki
Basin countries Finland
Surface area 145.49 km2 (56.17 sq mi)[1]
Max. depth 36 m (118 ft)
Surface elevation 69.5 m (228 ft)[1]
Islands 56 (Kärnä)
References [1]

Lappajärvi is a lake in Finland, in the municipalities of Lappajärvi, Alajärvi and Vimpeli.[1] It is formed in a 23 km (14 mi) wide, partly eroded meteorite impact crater.[2] The lake is part of Ähtävänjoki (Swedish: Esse å) basin together with Lake Evijärvi that is located downstream (north) of it.

The Lappajärvi impact structure is estimated to be 76.20 ± 0.29 million years old (Campanian stage of the Late Cretaceous time period).[3] Experts working on Finland's Olkiluoto nuclear waste repository project have studied Lake Lappajärvi to help them project how Finnish landscapes might look one million years in the future and beyond.[4]

An island in the middle of the lake, Kärnänsaari (Kärnä Island), gives the name to the black impact melt rock (impactite) found there, locally called kärnäite.[5]

The towns on the shore are Lappajärvi and Vimpeli. Although not very near any, the nearest major city is Seinäjoki.

References

  1. 1 2 3 4 "Finnish lakes larger than 40 square kilometers". Finnish Environment Institute. Archived from the original on 2011-07-25.
  2. ↑ "Lappajärvi". Earth Impact Database. University of New Brunswick. Retrieved 2009-05-24.
  3. ↑ "The Lappajärvi impact structure (Finland): Age, duration of crater cooling, and implications for early life". Schmieder M. & Jourdan F. (2013) Geochimica et Cosmochimica Acta, vol. 112, p. 321-339. Bibcode:2013GeCoA.112..321S. doi:10.1016/j.gca.2013.02.015.
  4. ↑ Ialenti, Vincent (5 July 2016). "Craters & Mudrock: Tools for Imagining Distant Future Finlands". The Long Now Foundation.
  5. ↑ http://www.gastro.physics.helsinki.fi/tutkimus/geo/kiintea/lappa.html
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