Lappajärvi is a lake in Finland, in the

municipalities A municipality is usually a single administrative division having corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate. The term ''municipality'' may also mean the go ...

Lappajärvi Lappajärvi is a municipalities of Finland, municipality in Finland in Southern Ostrobothnia regions of Finland, region. It is from Lappajärvi to Seinäjoki, to Kokkola and to Vaasa. The municipality has a population of () and covers an area ...

Alajärvi Alajärvi is a town and municipality of Finland. It is located in the South Ostrobothnia region. The town has a population of () and covers an area of of which is water. The population density is . The town is unilingually Finnish; there are few ...

and

Vimpeli Vimpeli (; sv, Vindala) is a municipality of Finland. It is located in the South Ostrobothnia region, northeast of Seinäjoki and northwest of Jyväskylä. The municipality has a population of () and covers an area of of which is water. The p ...

. It is formed in a wide, partly eroded

meteorite A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or Natural satellite, moon. When the ...

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...

. The lake is part of Ähtävänjoki ( sv, Esse å) basin together with

Lake Evijärvi Lake Evijärvi is a lake of Finland in Evijärvi, Southern Ostrobothnia region. The lake is part of Ähtävänjoki ( sv, Esse å) basin. See also *List of lakes in Finland There are 187,888 lakes in Finland larger than 5 ares (500 square m ...

that is located downstream (north) of it. The

impact structure An impact structure is a generally circular or craterlike geologic structure of deformed bedrock or sediment produced by impact on a planetary surface, whatever the stage of erosion of the structure. In contrast, an impact crater is the surface ...

is estimated to be 77.85 ± 0.78 million years old (

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...

age of the Late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

time period). Experts working on Finland's

Onkalo spent nuclear fuel repository The Onkalo spent nuclear fuel repository is a deep geological repository for the final disposal of spent nuclear fuel. It is near the Olkiluoto Nuclear Power Plant in the municipality of Eurajoki, on the west coast of Finland. It is being const ...

project have studied Lake Lappajärvi to help them project how Finnish landscapes might look one million years in the future and beyond. An island in the middle of the lake, Kärnänsaari (Kärnä Island), gives the name to the black impact melt rock (

impactite Impactite is rock created or modified by one or more impacts of a meteorite. Impactites are considered metamorphic rock, because their source materials were modified by the heat and pressure of the impact. On Earth, impactites consist primarily of ...

) found there, locally called kärnäite. The towns on the shore are

and

. Although not very near any, the nearest major city is

Seinäjoki Seinäjoki (; "Wall River"; la, Wegelia, formerly sv, Östermyra) is a city located in South Ostrobothnia, Finland; east of Vaasa, north of Tampere, west of Jyväskylä and southwest of Oulu. Seinäjoki originated around the Östermyra bru ...

. Earlier the lake was thought to have been an ancient volcano crater. In 1967, Swedish geologist Nils Bertil-Svensson examines kärnäite samples, and his article that Lappajärvi is a possible impact crater was published in

Nature Nature, in the broadest sense, is the physics, physical world or universe. "Nature" can refer to the phenomenon, phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. ...

journal in February 1968.

Gallery

File:Lappajärvi.jpg, Lake Lappajärvi File:Lappajärvi, july 2014.JPG, Lake Lappajärvi File:Lake Lappajärvi 2015-02-15.JPG, Frozen in winter File:Northern lights Lake Lappajärvi 20180315.jpg, Winter with northern lights File:Метеорит Шаттеркон.jpg, Lappajarvi impactite

References

External links

*
Lappajärvi impact structure

Lake Lappajärvi, a meteorite impact site in western Finland by Martti Lehtinen (1976)
{{DEFAULTSORT:Lappajarvi, Lake Impact craters of Finland Cretaceous impact craters

Impact crater lakes