Archipelago emerging from the sea
The landscape of the archipelago began to form after the last ice age. Gradually, many islands emerged from the sea because of the land uplift, which still is a continual phenomenon in Finland.
Over 10 000 year ago, the whole Scandinavia was covered with three-kilometre thick ice. Glacier weighted down the lithosphere and created a large dent. When the ice melted, the dent began to fill up with water and finally the Baltic Sea was born.
Land is still rising
After the melting of the ice cover, the pressure created by the ice sheets vanished and the earth's crust begun to rise. Due to the land uplift, the thousand islands of the Archipelago Sea were born. The little rocks came out from the sea, grew up and finally were united with the other islands and mainland. At the same time, new islets emerged from the outermost water area.
People inhabited the archipelago along with the forming of the island. Living conditions were favourable and the food was available.
Land is still rising. In the Archipelago Sea area, the land uplift is about four millimetres per year. Nowadays, the bay where your grandparents have swum in their childhood may be a flad or a gloe.
Traces of the ice age
In the Sinisimpukka (blue mussel) nature centre in Kasnäs, it is possible to step on the geological nature path. Ice age has marked its presence in the landscape of the archipelago as a ground smoothed rocks and round shaped islets. In the bedrock of the outer archipelago you can find Giant's kettles and trails of ice. In the inner archipelago the vegetations has already covered the most of them.
The ice age formation called third Salpausselkä goes through the archipelago. Final sight of it can be spotted in the island of Jurmo, where it dives under the water and continues to the outer sea.
Colder ahead?
Ice ages are discovered to be repeated regularly. As a result, we are now heading towards the colder period. On the other hand, the future is hard to predict for the human related global warming may confuse the cycles of nature.
Arctic Climate Impact Assessment: Impacts of a a Warming Arctic -report
