Kenn
01-Apr-06, 00:27
As many of you will be aware Caithness is largely composed of sedimentary rocks i.e. slate,clay and small pockets of Devonian red sandstone.These were raised from the ocean bed many millions of years ago.
Being soft rocks, they are easily permeated by water which when it freezes in winter causes them to crack and slide along the the tilt of the layers.
To the south and west are the volcanicaly formed granite ranges of Sutherland that extend all the way to The Great Glen along which runs a fault line and is an area that is still subject to earth tremors . (The Kessock Bridge is the only one in the UK that is built to withstand these.) This fault line is active and the tectonic plates are slowly making the glen expand.The pressure exerted by this is dispersed very slowly but moves inexorably north through the mountain ranges and will ultimately result in transference to the soft line of the northern slates and clays causing any cracks and fissures to rapidly expand.
Already the two main rivers of Caithness, one flowing north to Thurso and the other east to Wick have little land separation between their sources.With the expected effect of global warming which will result in much higher rainfall levels in the far north and the resulting saturation of the high hills will cause them to expand to cope with the extra volumn of water and with the added flow the erosion along their courses will increase in the same ratio.
It is therefore expected that when all these factors are taken into account istis a definite probablity that Caithness will become an island within the next two millenia.
www.national geo-physical.uk/NS/dept10apr1
Being soft rocks, they are easily permeated by water which when it freezes in winter causes them to crack and slide along the the tilt of the layers.
To the south and west are the volcanicaly formed granite ranges of Sutherland that extend all the way to The Great Glen along which runs a fault line and is an area that is still subject to earth tremors . (The Kessock Bridge is the only one in the UK that is built to withstand these.) This fault line is active and the tectonic plates are slowly making the glen expand.The pressure exerted by this is dispersed very slowly but moves inexorably north through the mountain ranges and will ultimately result in transference to the soft line of the northern slates and clays causing any cracks and fissures to rapidly expand.
Already the two main rivers of Caithness, one flowing north to Thurso and the other east to Wick have little land separation between their sources.With the expected effect of global warming which will result in much higher rainfall levels in the far north and the resulting saturation of the high hills will cause them to expand to cope with the extra volumn of water and with the added flow the erosion along their courses will increase in the same ratio.
It is therefore expected that when all these factors are taken into account istis a definite probablity that Caithness will become an island within the next two millenia.
www.national geo-physical.uk/NS/dept10apr1