BIRTH OF THE CRATER LAKE I CRATER LAKE GEOPARK AREA I SIGHTS AND ROUTES I METEORITE CENTER I EXPLORE I EVENTS I NEWS I GEOPARK PARTNERS

Europe’s Largest Crater Lake - created by an asteroid

Crater Lake Lappajärvi was born 78 million years ago when an asteroid orbiting the Sun for about 4.5 billion years collided with another similar asteroid between Mars and Jupiter. As a result of the collision, a meteorite with a diameter of more than one kilometer hit Earth at a cosmic velocity (approximately 10-40 km/s) near what is now Lappajärvi. The collision caused enormous destruction, destroying everything alive within a few hundred kilometers and creating a crater whose elevation was 750 meters and a diameter of 22 kilometers.

Tectonic plates have moved millions of years and ice ages have flattened the crater. To this day the crater is surrounded by elevated edge that can still be seen from Lakeaharju (in Vimpeli) and Pyhävuori (in Alajärvi) offering spectacular views of the Crater Lake. Additionally, you can see the largest island of Lappajärvi called Kärnäsaari, which is the original uplift caused by the collision.

The asteroid that gave birth to the crater was destroyed in the explosion. As a result of the crush, several new rock types were formed, of which the most important are kärnäite and suevite. Kärnäite, as very hard rock, has been protecting Kärnäsaari island from further erosion. Kärnäite contains a lot of rock fragments and minerals in a completely melted groundmass. Based mainly on the visual observations, Lake Lappajärvi was still considered to be a volcanic crater until 1970s. In 1976, Martti Lehtinen in his doctoral dissertation proved the celestial origin of the crater. Kärnäite can still be seen as unique out crops.

Suevite consists of material that was floating in the air from the crater. It consists of rock and mineral fragments, crushed rock, which has mixed with molten rock. Suevite is a fragile mixture of crushed and melted pieces. There are rare diamonds found in Suevite and can be found only in three craters in the world. Suevite can only be found in the deep drillhole samples and gravel deposites south and southeast from the crater lake.

 

Current measurements of Lappajärvi: 17 km x 35 km.

Maximum depth 36 m, average depth 7.4 m.

 

View to the Europe’s largest crater lake, Lappajärvi, seen from the observation tower in Lakeaharju Vimpeli. In Lakeaharju you can walk on the crater rim, that still rises 100 meters above lake Lappajärvi. Original crater rim is estimated to have been 750 meters high.


Explore meteorite exhibition in Lappajärvi

Explore the birth of Lake Lappajärvi and find out about meteorites and asteroids in Meteorite Exhibition in Lappajärvi. VR glasses will take you on an exciting journey - A spaceship will take you to the world of asteroids between Jupiter and Mars, where the asteroid which created Lappajärvi also comes from.  Read more here.