UNESCO World Heritage Site: High Coast
The High Coast is located on the west shore of the Gulf of Bothnia, a northern extension of the Baltic Sea. The area covers 142,500 ha including a marine component of 80,000 ha, which includes a number of offshore islands. The irregular topography of the region - a series of lakes, inlets and flat hills rising to 350 m - has been largely shaped by the combined processes of glaciation, glacial retreat and the emergence of new land from the sea. Since the last retreat of the ice from the High Coast 9,600 years ago, the uplift has been in the order of 285 m which is the highest known 'rebound'. The High Coast site affords outstanding opportunities for the understanding of the important processes that formed the glaciated and land uplift areas of the Earth's surface.The Kvarken Archipelago (added in 2006 as an extension to the World Heritage site of the High Coast) numbers 5,600 islands and islets and covers a total of 194,400 ha (15% land and 85% sea). It features unusual ridged washboard moraines, "De Greer moraines", formed by the melting of the continental ice sheet, 10,000 to 24,000 years ago. The Archipelago is continuously rising from the sea in a process of rapid glacio-isostatic uplift, whereby the land, previously weighed down under the weight of a glacier, lifts at rates that are among the highest in the world. As a consequence of the advancing shoreline, islands appear and unite, peninsulas expand, lakes evolve from bays and develop into marshes and peat fens. This property is essentially a "type area" for research on isostacy; the phenomenon having been first recognized and studied here.
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