Archive for the 'Coastal processes' Category

3rd December 2009, Thursday

Detached moorlog


The recent storms have boken off slabs of moorlog,which now lie scattered along Pett beach. They originate from about 5000 years ago when the sea level was lower and forest extended into what is now Rye Bay. The returning salt water killed then pickled the forest, fallen onto its bed of blue clay, blanketing it with silt.
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4th January 2009, Sunday

Then and now 9

Some further photo’s showing the extent of change on the Dungeness shingle beach, this time Dungeness Point in 1946. The most obvious change is the extent of superbly vegetated ridges where the power station is now.

There is also the present-day grid of tracks to the east coast which are the “beach feeding roads”. One of the consequences Read the rest of this entry »

27th December 2008, Saturday

Then and now 8

One part of the Dungeness shingle beach that has shown considerable natural change over the years is the south coast.  This map shows Wickmaryholm Pit, on the south coast of Lydd Ranges in 1878.  The is a natural shingle wetland and originally consisted of two areas of open water, divided by a tongue of shingle.  This pit was once much further inland and fresher, as witnessed by the remains of the freshwater aquatic plants such as spiked water milfoil Myriophyllum spicatum in its peaty sediments. To the east was the smaller Abnor Pit and to the west  was Tarts Cottage.

These were a fantastic series of Ordnance Survey maps covering the whole of the UK in amazing detail. It never fails to amaze me how they managed to be so accurate without the use of aerial photographs.

After this map was made Read the rest of this entry »

19th December 2008, Friday

Then and now 6

This 1946 aerial photo shows the Oppen pits on Dungeness as a series of unshaded wetlands within a vast area of dry shingle, with fascinating ridge patterns showing the evolution of this bit of the beach.  How I would have loved to have visited them in this period, when they really must have felt isolated.  Since then they have suffered the triple whammy of grazing abandonment, lowered water tables, and damaging peat fires.
1946
 

And in 2008: Read the rest of this entry »

5th August 2008, Tuesday

The Pits!

The natural freshwater pits at Dungeness, with their Transition Mire communities are thought to be unique to Dungeness, but the geomorphological processes that formed them are not, and at Rye Harbour there are similar, though younger features near the Lifeboat Station that show an earlier stage in the development of these sorts of wetland communities. All of these ponds formed as shingle ridges developing along the shoreline left low lying hollows that became open water lagoons. They are very rare natural features, primarily because shingle beaches themselves are a rare habitat, and are much more interesting than the artificial gravel pits that disfigure these shingle habitats.

Natural pits at Rye Harbour

Being closer to the sea the Rye pits still show a brackish influence, demonstrated by the presence of sea club-rush Bulboschoenus maritimus and bulrush Scirpus tabernaemontani. There are also stands of Read the rest of this entry »

17th February 2008, Sunday

Why Dungeness vegetation comes in stripes

One of the first impressions of Dungeness is that the vegetation is stripey. This unusual phenomenon can be viewed on the early false-oat-grass grassland and is fixed as the vegetation ages. Why?

It is all down to the action of the waves. As well as throwing up the shingle in characteristic ridges the gravel is sorted into bands of coarse and fine shingle

 Wave-sorted shingle

This can be observed in the photograph above, with fine pea beach on the right and coarser stones to the left. This is not the only wave sorting that goes on, however. As you travel up the coast from Lydd on Sea to Greatstone the stones get larger and larger. Greatstone is well named. Read the rest of this entry »

4th January 2008, Friday

More on the strand line vegetation at Dungeness

On the 30 December I wrote a post about the unusual and internationally important vegetation communities that grow just above the high tide line (or strandline) at Dungeness and Rye. This photograph shows a particularly well developed example of this vegetation. It was taken in August 1998, and shows Babbington’s orache – the pale green patches of low growing vegetation, amongst dark clumps of sea weed washed up by the sea. Sea kale, a relative of the cabbage replaces the annual vegetation slightly further inland. This is the best patch of this vegetation I have ever seen at Dungeness. What happened next?

Strandline vegetation - Dungeness

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29th December 2007, Saturday

An ancient feast, and other surprises

Walking across the shingle on the Lydd Ranges coast on Wednesday I came across a horde of cockle shells near Galloways, with the odd dog whelk thrown in. They had been dropped in a cluster, and judging by the numbers of slow growing lichens darkening these pale shells they are clearly an old feature. Is this the result of a bird (perhaps a gull or a crow) gathering the shells and feasting on them at a particular roost spot, or are they signs of a meal by people foraging on the beach before it became regularly fired over by the army? The high cover of lichens on the shells shows that this patch of shingle has been left undisturbed for a long time.

 shell horde.JPG

Further south from this Read the rest of this entry »

1st December 2007, Saturday

The Mobile Coast II

If any picture sums up the changeable face of the Dungeness Coast (yes I said Dungeness as in the shingle beach) it is this one, taken on the north-east edge of the Dungeness National Nature Reserve today.

Marram Grass on Greatstone Beach

Ten years ago this was vegetated shingle. Over the past ten winters increasing quantities of sand have blown onto the shingle and now marram grass Ammophila arenaria is well established. The dunes are likely to start building upwards quickly if this trend continues, as they have done to the north of the Romney Sands car park.

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30th November 2007, Friday

The Mobile Coast

On the 27 September 2007 I wrote about the Open Pits, a superb series of natural ponds on the shingle at Dungeness. One of these natural pits is quite different, Wickmaryholm Pit on Lydd Ranges. It is older than the rest and its days are numbered.

Wickmaryholm Pit

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