Söderfjärden

Söderfjärden
Söderfjärden is visible as the hexagonal cultivated area in this Landsat image
Impact crater/structure
Confidence	Confirmed
Diameter	6.6 kilometres (4.1 mi)
Depth	300 metres (980 ft)
Age	640 Ma
Exposed	No
Drilled	Yes
Location
Country	Finland
Municipality	Vaasa

View of the basin of the crater remnant from Öjberget, a hill that belongs to the crater rim

Söderfjärden is a polder in Ostrobothnia, western Finland, 10 kilometres south of the town of Vaasa. The plain is in an impact crater which was made at least some 640 million years ago (Proterozoic, near the end of the Cryogenian). The crater's diameter is 6.6 kilometres (4.1 mi) and its maximum depth is 300 metres (980 ft). It is filled with Cambrian sandstones leaving only the outer rim visible. There is also a central uplift, which is buried. After rising from the sea due to post-glacial rebound, Söderfjärden was a wetland but was later drained with help of a pump station. It is currently cultivated and is clearly visible from air as a large hexagonal field. This makes Söderfjärden unique among the other impact structures in Finland which are at least partially below sea level. The area of the basin is divided half and half between Vaasa and Korsholm, with a small corner belonging to Malax.

See also

• Impact craters in Finland

External links

• Sundom village travel information page about Söderfjärden.
• Söderfjärden in Finnish impact structures homepage.
• The homepage of a local exhibition site, called Meteoria, in Swedish, Meteoriihi in Finnish, describing the area. Ria (riihi) is a kind of barn, where crop is dried, and the building looks like one.
• Google Earth view