Lappajärvi is the largest lake near the lower right corner.
|Surface area||145.49 km2 (56.17 sq mi)|
|Max. depth||36 m (118 ft)|
|Surface elevation||69.5 m (228 ft)|
Lappajärvi is a lake in Finland, in the municipalities of Lappajärvi, Alajärvi and Vimpeli. It is formed in a 23 km (14 mi) wide, partly eroded meteorite impact crater. 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). 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.
- "Finnish lakes larger than 40 square kilometers". Finnish Environment Institute. Archived from the original on 2011-07-25.
- "Lappajärvi". Earth Impact Database. University of New Brunswick. Retrieved 2009-05-24.
- "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.
- Ialenti, Vincent (5 July 2016). "Craters & Mudrock: Tools for Imagining Distant Future Finlands". The Long Now Foundation.
- "Archived copy". Archived from the original on 2012-07-31. Retrieved 2012-04-09.
- Media related to Lake Lappajärvi at Wikimedia Commons
- Lappajärvi impact structure
- Lake Lappajärvi, a meteorite impact site in western Finland by Martti Lehtinen (1976)