Changes at Langney Point
Changes at Langney Point / The Crumbles
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Langney Point is believed to have originated as a spit or bar which grew across the shallow waters of Pevensey Bay. Boreholes suggest that it began as a sandy beach for the coarse shingle overlies a sandier deposit. The shingle is mostly flint and there is strong evidence that the Chalk cliffs of Beachy Head contribute a good proportion of the source material. It may be observed that the pebbles on the west side have a coating of chalk which decreases eastwards, as does the number of chalk clasts.
The headland consists of a series of parallel ridges trending approximately south-west to north-east with a more eastward aspect towards Pevensey. Along the southwest margins the ridges are truncated by erosion and the actual point has probably migrated north-eastwards in the same manner as the point of Dungeness in Kent. Since 1806 the shingle has accumulated in places along the point north-east shore by as much as 300m.
It would appear that Langney Point initially built up very quickly as there is little evidence of it before the sixteenth century, yet by the time of the Armada Survey of 1587 (Fig 7a) a shingle foreland had developed which projected over 2km seaward. Since that time the point has been depleted. The Armada Survey shows a large expanse of marsh behind the shingle foreland between Langney and Pevensey Castle. Drainage of the marsh was poor as the only contact to the sea was by a small stream which chained across the shingle to Langney Point itself. The stream is still in evidence today (though it no longer reaches the sea). By 1648, Bleau's map (Fig 7b) shows the marsh behind the shingle reclaimed and the stream which chained to the point terminates in a pond (now Crumbles Pond). The map sites the pond on the mainland though in actual fact its situation was probably within the foreland. The beach is of similar size and shape as on the Armada Survey map.
On Budgen's map of 1724 (Fig 7c) the beach extended 4.6km from south-west to north-east and the maximum width of shingle was 2.1km. The map by Yeakell and Gream (Fig 7d) is based on the 1778-83 Yeakell and Gardner map used for the other locations. The width of the shingle is the same as in 1724, but the point is located 250-300m to the northeast and the shingle appears to have been carried northeast along the coast. The example taken for the nineteenth century was compiled by the Harbour Commission (Fig 7e). The Martello Towers built as defence against possible Napoleonic invasion in 1806 are shown on the map and provide points of reference for subsequent coastal changes. Out of an original 14 which were built on the shingle only 4, including the Grand Redoubt, remain at the present day. In the 60 years from 1780 to 1840 the point retreated 700m to 1.4km in width and migrated over 500m to the northeast, a rate of migration of over 8m per annum. Migration resulted from the erosion of material on the south-western side of the point and deposition on the northern.
In 1876 the detailed Ordnance Survey 6 inch map shows the shingle reaching 1350m in width and the Crumbles Pond being infilled with waste brought by tramway from Eastbourne. Twenty three years later the point had retreated by a further 62m. During this century, groyne construction has checked erosion, and there are negligible differences in the position of the point on the various editions of the Ordnance Survey maps (Figs 7f and 7g). In recent times there has been a small removal of shingle on the north side of the groynes in the lee of the point where the tidal currents are strongest whilst there has been no replenishment from the other side of the point where groyning has been more successful in curbing erosion.
In the last 20 years the major changes involve the construction of
Sovereign Harbour Marina
opened in 1993.
References and further reading.
Redman, J.B. 1851-2. On Alluvial Formations and Local Changes of the South Coast of England. Proceedings of the Institute of Civil Engineers. Vol 11 pp 162-226.
Steers, J.A. 1964. The Coastline of England and Wales. Cambridge U.P.pp 312-314.
3 Robinson D.A. and Williams. R.B.G. 1983. The Sussex Coast Past and Present. In Sussex, Environment, Landscape and Society Eds. The Geographical Editorial Committee. University of Sussex, Alan Sutton, chapter 3 p 58.