29 Aug 2007
The Rise and Fall of Sea Levels and Civilisations.
Just back from a few glorious days on the Scilly Isles, somewhere I have never been before, but will certainly go back to. What a beautiful place. For those who don’t know, they are a small collection of islands off the south west coast of Cornwall, about 45km west of Land’s End. They were formed as part of a collision between continental plates 200 to 300 million years ago, which forced up granite intrusions, which over time have eroded, leaving the landscapes which run from Dartmoor, down through Cornwall and then out under the sea, rising to put in a last appearance at the Scillies. As well as being a stunningly clean and beautiful place, being there also focused my mind on sea level rise, as the rising and falling of the sea has been central to the evolution of culture and ecology there over time.
During the most recent Ice Age, (about 18,000 years ago) the sea level around the Scillies was as much as 75 metres lower than it is now. What we see now as individual islands were, as recently as 3,000 years ago, one single island. In one shop I saw this beautiful poster (I didn’t see it anywhere else as postcards, hence my not that good photo of it, right) which, through the clear blue (but unfortunately freezing) waters surrounding the island allow one to see the underwater landscape around the islands.
Indeed, there are legends in both Scilly and Cornwall of a lost land between the two, called Lyonnesse. Legend tells of a land of rich pastures, abundant orchards, beautiful people and a city called Lions. It was said that from its highest point you could count the steeples of 140 churches. Legends persist of sailors being able to still occasionally hear the bells tolling beneath the waves, and there is apparently a family in Cornwall, called Trevelyan, who claim to be related to the only man who escaped the inundation, he scrambled out on his horse, which lost a shoe in the flight; their family crest featuring 3 horseshoes.
It is thought that much of this legend is to do with the Bronze Age inhabitants of the islands who first arrived there 4,000 years ago when they were all connected. Their submerged field walls and round houses, some of which can still be seen at low tide, may well have been what inspired the storytellers to begin to weave the legends of Lyonnesse.
When you walk around the Scillies now, one is struck that what appear to be islands, are in fact the tops of mountains, and that the direction of history and climate means that they will, in time, go the way of the homes of their Bronze Age ancestors. Hugh Town, the main settlement on the main island, St. Mary’s, is perilously close to sea level, being just a few feet above the sea.
One night in the hotel we stayed in, we watched a fascinating programme about India and its pre-Raj history. It built up, through DNA analysis, archaeology and climatic reconstruction, a compelling case that present day India came from a civilization in the Indus valley, now long gone, which was forced to migrate east when the rivers on which they depended dried up. Their argument that climate is one of the principle drivers behind settlement resonated as we sat there on the Scillies.
If we fail to prevent runaway climate change, what tales will be told of our civilizations the lie beneath the waves? Will we be talked about by future inhabitants of this earth as having been strong and beautiful with rich pastures and abundant orchards, or as a society whose greed and inactivity brought about its own demise? What legends might those on the high ground of the Peak District tell of the now-flooded lowlands of East Anglia? Sitting on the beach in Scilly, looking out across the islands, looking down into the waters, sea level rise felt very present and an integral part of our genetic memories.
By the way, if you’re thinking “miserable git… goes to the Scilly Isles and spends the whole time fretting about sea level rise”, it was an occasional muse… I also spent a lot of time doing other things! I blame the trip over to the Scilly Isles on the boat, which for the nervous sea traveller does begin to get one thinking apocalyptic thoughts… while walking around the boat, feeling seasick and altogether queasy, I came across, in the lounge, a poster called “Shipwrecks of Scilly”, a map of all the shipwrecks on the rocks around the islands (there have been many). Luckily the crossing was relatively smooth.