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Topographic features of the Kvarken Islands in Finland

The Kvarken Islands are the first project in Finland to be listed as a World Natural Heritage Site, 150 kilometers from Sweden’s high coast. This archipelago formed by moraine rocks, and its rising topography, is a typical area for studying isostatic phenomena. Also affected by glaciation, the high coast of Sweden and the Kvarken Islands of Finland have different topographical characteristics.

Introduction

English name: Kvarken Archipelago/High Coast

Selected time: 2000 2006

Selection basis: N(i)

Location: N63 18 00 E21 18 00 (Kvarken Islands, Finland)

N63 00 E18 30 (Swedish High Coast)

Heritage Number: 898

Terrain features

The High Coast is characterized by a steep, rocky coastline with hills as high as 350 meters, while the Kvarken Islands are made up of low-lying moraine islands, the highest point of which is only 20 meters above sea level. These two regions happen to fully represent the complex terrain development after the Ice Age. The Kvarken Islands cover an area of ​​194,400 hectares, with land accounting for about 15% of the total area and the remaining 85% being ocean. It has 6,550 islands of various sizes and a total coastline of 2,840 kilometers.

The water depth in this area is only about 25 meters, and it is covered with ridged moraine like a washboard. The most special of these is the Ostrobothnia Plain, a large area that is very complete and composed of De Greer moraines. It is estimated that it was formed about 10,000 to 24,000 years ago. It fully demonstrates the gradual melting of glaciers on land after the Ice Age. process. The land that was originally submerged under the pressure of huge glaciers is rising at an alarming rate. The archipelago will increase its land area by 100 hectares every year, with an average rising rate of 8-8.5 mm per year, the fastest in the world.

The continuously changing terrain has resulted in the continuous extension of the coastline, the increase of islands, and the bays gradually forming lakes and then developing into swamps; if the speed remains unchanged, after 2500, there will be connected land in the Kvarken Strait between Finland and Sweden. The Gulf of Niah may become the largest freshwater lake in Europe. The unique terrain and ecological environment of the Kvarken Islands record an important stage in the development of the earth. The new land rising from the seabed has not experienced erosion and destruction, which helps scientists understand the history and biology of the earth since the Ice Age Evolutionary processes, and for geological studies, are extremely representative.

Added to the World Heritage list in 2000, Sweden’s High Coast features soaring rocks where the land uplift after the Ice Age is clearly visible. Kvarken, on the other hand, is full of low, flat washboard-shaped moraine islands, the highest point of which is only 20 meters above sea level. The most obvious and most spectacular place is the De Geer Moraine formed by the melting of the continental ice on the Ostrobothnia Plain 10,000 to 24,000 years ago, showing the gradual disappearance of the glaciers of the continental ice. The formation of the De Geer moraines is unique and representative of the region’s frequent uplift and the presence of hummock moraines and other formations in the cross-section of glacier ridges.

Evaluation by the World Heritage Committee

The Kvarken Islands and the High Coast lie in the Gulf of Bothnia, extending north into the Baltic Sea. The Kvarken archipelago of 5,600 islands is dotted with washboard-like ridged moraines that formed a large, remarkably intact continental ice sheet between 10,000 and 24,000 years ago. The archipelago is in the process of continuous rise. The land that was originally oppressed by huge glaciers and sunk to the bottom of the sea is rising at an astonishing speed, and the uplift speed is the highest in the world. The continuously changing terrain has resulted in the extension of the coastline, the increase of islands, and the gradual formation of lakes in bays and then swamps.

The high coast has also largely been formed by the glacial processes of merging, in which glaciers retreated and new land emerged from the sea. Since the last glacier retreated from the high coast 9,600 years ago, it has uplifted by 285 metres, the highest “bounce” recorded. The heritage offers excellent opportunities to understand the important processes of glacial formation and land uplift on the Earth’s surface.