TV5496TV5496 covers a central section of the Seven Sisters Country Park. Like the adjoining coastal grid squares, the landscape is largely shaped by the processes of coastal erosion. No attempt has been made by The National Trust to create coastal defences and, indeed, it is their policy to allow the cliffs to be eroded so that they remain white, vertical and as a source of beach material like chalk and flint which lessen the impact of destructive, storm waves.
The extensive wave-cut platform gives an indication of where the sea-facing cliffs once stood and the degree to which erosion has taken place at a rate of approximately one metre per year. Present day erosion is indicated by nick points, caves and rock falls of chalk and flint. Particularly in places where there is a line of weakness, such as a dissolution pipe, water from the saturated and porous chalk percolates through the chalk cliffs and issues out at the base of which is underlain by impervious clay. It is at this weak point that erosion often takes place in the form of a wave-cut notch. One of the attached photos shows a large beach boulder which has been acted on by various types of erosion and weathering. Another photo shows how the impact of storm waves and contact with salty water has reduced the remains of the S.S. Oushla and the First World War U boat, thought to be UB-121, into almost unrecognisable forms of corroded metal.
While
NO5496 provides an environment and many opportunities for the geologist, the geomorphologist and geographer to study the landscape in a reasonably accessible location, great care should be taken when walking on the cliff edge and on the beach below. Cliff collapse is unpredictable and this coast is subject to such occurrences.
Suggested discussion points could include coastal erosion, safety measures and coastal wrecks.
Andrew Diack, B.A., (Hons)
TV5496 : Physical, chemical and biological weathering of a rockTV5496 : The wrecks of the S.S. Oushla and U B-121TV5496 : Coastal caves at Flagstaff Bottom, Seven SistersTV5496 : Rockfalls on the beach at Baily's Hill, Seven SistersTV5496 : Freshly exposed chalk marking erosion on cliff face, Seven Sisters