Lumparn with the impact structure area in grey
Impact crater/structure
Diameter9 km (5.6 mi)
Age~1000 Ma
LocationFasta Åland
Coordinates60°9′N 20°6′E / 60.150°N 20.100°E / 60.150; 20.100Coordinates: 60°9′N 20°6′E / 60.150°N 20.100°E / 60.150; 20.100
Country Finland
DistrictÅland Islands
MunicipalitySund, Lumparland, Lemland & Jomala
Lumparn is located in Finland
Location of the crater in the Botnian Gulf

Lumparn (fi. Lumpari) is a large bay devoid of islands in the main island of Åland, Finland, bordered by Sund to the north, Lumparland to the east, Lemland to the south and Jomala to the west.


Most of the bay fills a nine kilometer wide impact crater. The crater is estimated to be about 1000 million years old (Proterozoic).[1] The depression was originally believed to be a rift. Extraterrestrial origin was first proposed in 1979, but not until 1993 was the impact structure finally confirmed. Long shatter cones have been discovered in the southwestern part of the bay. The crater is filled with sediments, between Pleistocene sediments and crushed rapakivi granite bedrock there is a layer of Paleozoic (Ordovician) limestones. This makes Lumparn one of the few places in Finland where fossils have been found.

The bay has also previously been referred to as Lumpari[2] in some Finnish documents, though the Research Institute for the Languages of Finland does not list Lumpari as in current usage.[3]


Panorama over Lumparn, seen from the south coast. On the horizon, a small part of Sund is just visible.

See also


  1. ^ "Lumparn". Earth Impact Database. Planetary and Space Science Centre University of New Brunswick Fredericton. Retrieved 2009-08-15.
  2. ^ Lumpari World Water Features Database | Archived 2007-09-27 at the Wayback Machine
  3. ^ Svenska Ortnamn i Finland Archived 2007-11-13 at the Wayback Machine, The Research Institute for the Languages of Finland, see "Lumparn"

External links

  • Lumparn impact structure (archived link)
  • (in Finnish) The Landforms of Finland
  • Svensson, N.-B. (1993). "Lumparn Bay: A Meteorite Impact Crater in the Aland Archipelago, Southwest Finland". Meteoritics. 28 (3): 445. Bibcode:1993Metic..28S.445S.
  • Map of Lumparn