Ice has covered Shetland several times over the past two million years. However, Shetland was never as deeply buried as Scandinavia or mainland Scotland, and so does not display a similar deep carved landscape. Here, the glaciers gently scoured the landscape into the low, undulating hills and shallow lochs we know today.
On one occasion Scandinavian ice pushed its way across to Shetland. Our evidence for this is the ‘Dalsetter erratic’ – a boulder found in the South Mainland. This rock is made of Tonsbergite, a type of rock found only in Norway.
A Mountain Climate
For much of the time during glacial periods, Shetland was covered by tundra rather than ice. The granite block-fields and gravely terrain (fellfield) on Ronas Hill - Shetland’s highest hill at 450m - are the result of repeated freezing and thawing which cause the rock slowly to crumble.
A Flooded Landscape
Today in Shetland you are never more than 5km from the sea but it wasn't always like this. During glacial times, a large amount of water was locked away as ice, making sea levels considerably lower. Only when the ice began to melt some 12,000 years ago did the seas begin to rise.
Much of Shetland became a flooded landscape as the lower ends of its valleys drowned beneath the rising waters. Numerous sea inlets - the ‘voes’ now characteristic of Shetland - were formed. In addition, rising sea levels reworked sediments to produce stunning sandy or shingle beaches, bars and tombolos. The sand tombolo at St. Ninian’s Isle is one of the finest in Europe.
The Force of the Sea
The west coast of Shetland is subject to the full force of the Atlantic Ocean. In fact it is one of the highest energy coastlines in the world. Ferocious storms have carved spectacular cliffs that drop into deep sea, while caves, stacks, arches and geos are commonplace. A visit to the Eshaness coast or to Papa Stour will give you some idea of the awesome power of the sea.
It's Our Fault!
Several large faults run roughly North to South through Shetland. The landmasses on either side of them have moved relative to each other, horizontally or vertically, sometimes by tens of kilometres. Because of this we can see dramatically different landscapes existing side by side. The largest of these faults – the Walls Boundary Fault – can be seen at the Back Sand, Ollaberry.