Two volcanoes in one day
|01/05/2012||Filled under Clyde, Scotland|
I believe I may have mentioned Davaar Island before in this blog, about it being the only remaining part of a volcanic vent, sometimes referred to as a ‘plug’, which lies in the mouth of Campbeltown Loch. It turned out to be a convenient piece of rock on which to erect a lighthouse, which no doubt saved David and Thomas Stevenson a lot of hard construction work back in 1894. They knew what they were doing because just eighteen nautical miles away to the south-east is another similar ‘plug’ on which this pair of engineers had erected a lighthouse eight years earlier. This rocky lump is known as Ailsa Craig and it rises steeply out of the Firth of Clyde to a height of 338 metres (1,110 feet), has an area of only one third of a square mile and although the human population is zero, it is home to around 36,000 pairs of gannets. Puffins too are staging a comeback here after being wiped out some years ago by rats arriving on ships servicing the stone quarrying activity. The rats themselves were subsequently exterminated (in an effort to try to put things back as they were) and now we once again have puffins burrowing into the thin topsoil of the island.
All interesting facts about 500 million year-old extinct volcanoes, or what is left of them. But I learnt recently that someone has discovered some bits of Ailsa Craig scattered about the English countryside, a long way away. The distinctive ‘blue hone’ granite which is found on the island and shaped to make the splendid curling stones used in the Winter Olympic Games, has such a unique quality that when chunks of it were found in a field in the English Midlands this led some keen geologists to investigate whence they came. Their amazing conclusion is that they (the stones, not the geologists) were brought there by a glacier which must have picked some bits up and carried them away southwards. All this happened a few years ago, of course but I find this snippet of information quite fascinating, not simply because of the distance the rock has travelled. My mind goes into a spin at the thought of someone examining these few grubby bits of stone, found just lying about, in an effort to work out where they came from. Has every piece of the land we live in been similarly examined in this detail, I wonder? Is there someone being paid to do this work? And if so, where can I apply for the job? Where does it all end? Surely every speck of rock and soil across the land has not been examined so thoroughly as this would seem to suggest. I feel fairly certain that the stones I dug up in our front garden whilst bedding in some herb plants the other day have never been examined before. But who knows what riches would be discovered if we did look at everything in this sort of detail?
What really prompted me to find out all these fascinating details was that last Saturday morning we sailed Cirrus out of Campbeltown Loch past Davaar Island and set a course for Ailsa Craig. A fresh north-easterly wind was blowing, forcing us to dress up warmly against the cold, but despite this we hardened the sheets and set a direct course for the island. As usual when at sea we switched on our GPS chartplotter, a small piece of electronics which removes all the cleverness and mystery from small boat navigation and which when connected to the tiller even steers a good course for us, then we settled back to keeping watch and admiring the guillemots in the water around us. They always seem to wait until the last second before panicking and diving out of sight. Today, however, we are thwarted by ‘War Games’ (more properly called ‘Joint Naval Exercises’) going on in the Clyde. It seems the Admiralty, in its wisdom, has the power to turn off GPS radio signals in any particular area whenever they want and they do this to make life more exciting for the officers on their ships regardless of whoever else they inconvenience. GPS signals are used most heavily by navigation systems fitted in cars and telephones these days so we know we are not alone as we curse those who wield such power so recklessly. Fortunately the target of Ailsa Craig is almost unmissable – it is the highest thing around for many miles – and the few grey-painted navy ships we do see keep well clear of us. We pass just one other yacht, on the way out, then pass it again on the return journey where with the wind free, Cirrus takes off across the sea like a scalded rabbit, a white streak of foam streaming out from her stern. When Kate takes her favourite spot on the bow she does so it because it is dry, comfortable and a rather fun place to be. The wind may be cold but it is deflected upwards by the hull so with feet dangling just above the water and the sound of our twin bows splashing beneath us we both enjoy sitting here and watching the scenery pass by. Some added pleasure may come when we are joined by dolphins riding the bow waves – but sadly not on this occasion. Davaar Island is ahead now and as we glide back home to our mooring the wind falls light at last and all is quiet. Somewhere out at sea the navy is still simulating World War Three or the D-Day landings with as much realism as they can create but we spend the night on board rocked asleep by gentle movements as the remaining breeze drifts across the loch. We decide that two volcanoes is quite enough for one day.