Showing posts with label global warming. Show all posts
Showing posts with label global warming. Show all posts

Monday, 24 March 2008

High tides Ramsgate surges and global warming.

We often get fairly high tides in Ramsgate as you can see from the picture taken last November click here to see more pictures of this high tide. The real problem comes when a high tide is combined with a storm coming from the east or south, fortunately this doesn’t happen often. The prevailing winds in this part of the world are from the north and east so it’s mostly Margate and the north Thanet coast that gets the worst of the problems.


We get two types of extra high tide the first type is a spring tide shown in the video, this is caused by the combined gravitational pull of the moon and sun and mostly occurs in spring and autumn. The second type is a tidal surge this is caused by barometric pressure over the sea i.e. it’s weather related and is sometimes combined with a storm.

We also have the effects of sea level rises caused by global warming to consider, if you look at the figures for Dover tide gauge for the last 60 years it appears the sea level has risen about 10 cm or 4 inches during that period. This really isn’t enough to make any difference at the moment and scientists are still fairly uncertain about both how much the sea will rise or how quickly.
I am playing it safe on this one and am doing a lot of recycling, have cut down on all forms of motorised travel (Mostly by doing nearly all of the shopping in Ramsgate which also helps support the local shops.) and have sold my big car.

Sunday, 23 March 2008

Thanet and the Wantsum

With all the recent talk of allowing the sea defences to fail that stop Thanet from becoming an island again, I thought some historical background would be helpful to some of you.

When the last ice age ended about 10,000 B.C. the glacial melt down caused by the global warming resulted in sea levels to rising by about 100 meters, separating the UK from Europe. By about 3,000 B.C. the level had filled in the ancient waterway known as the Wantsum.

The geological information suggests that in Roman times the Wantsum a considerable waterway about two miles wide and 30 feet deep. Until it silted up it was the main sea route between the Thames and the North Sea, and the English Channel. Going round the North Foreland has always represented a nautical challenge. It is our local mini Cape of Good Hope or going round the Horn.

If you consider the seas rising leaving Thanet an island, because it is higher and the surrounding land is lower, what you have to start with can be thought of as the typical children’s concept of an island, a chalk hill with a flattish top poking out of the water.

The north, east and south coasts being subject to the full force of wave action were eroded away, the result being our chalk cliffs. The west and southwest coast of Thanet faced the UK mainland and were subject to the gentle silting up of the Wantsum channel. This silting up was a very slow process and without large scale land reclamation Thanet would probably still be an island today.

From about 1,000 AD the two great monasteries of Minster and Canterbury owned most of the land around the Wanstsum and from about this time the monks started building dykes and reclaiming land.