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Coastal Erosion - Walton-on-the-Naze - Background Information
Naze Notes - Cliff Erosion
~ Field Study Diagrams ~
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________________________________________________________________________________________________________________________________
________________________________________________________________________________________________________________________________
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NAZE GALLERIES:
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Formation of a Cliff Rotational Slump
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YouTube:
Field Trip...
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Three Dimensional View
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The 'rotational failure surface' [slideplane] at the Naze occurs between the upper porous rock and the impervious clay beneath
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___________________________________
For further information,
click on the diagrams
__________________________________
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Development of 'scarp', 'slideplane' & 'toe'
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The Drainage Problem
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Surface water causes the soft, porous rock above the impervious clay to become waterlogged, encouraging mud slides. The eroded material is carried away from the cliff toe by longshore drift. Most damage occurs during the winter when the heavier rainfall causes the water table to rise and storm tidal surges occur more frequently.
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Anatomy of a Rotational Slump
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'Minor scarps' occurs as the slumped material begins to break up. 'Crown cracks' are signs of further land losses to come. 'Transverse cracks & ridges' develop as the 'foot' of the eroded material is exposed to weathering - and the 'toe' of this will finally reach the shoreline where inevitable wave action will follow.
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Cross Section of Eroded Naze Cliff Strata:
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Red Crag | Alluvial Silts | Glacial Sand & Gravel
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_______________________________________________________________________________________________________________________________
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NAZEMAN EDUCATION TRUST
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NAZEMAN EDUCATION TRUST
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counter reset:
October 2007
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