The sea encroaches on the land. On November 

 30, 1936, high tides caused ciiffs of giaciai 

 sands and clay on the east coast of England, 

 near Lowestoft, to crumble and collapse 

 into the sea. Abandoned houses near the 

 edge were left in shambles. 



the cracks is compressed and so helps break them up. Whenever 

 the waves enclose a pocket of air as they break against the clifF, 

 great pressures may be built up within the pockets, then with an 

 explosive force these pressures send spray high into the air, spray 

 capable of carrying pebbles and rocks. In the United States, off the 

 coast of Oregon, the roof of Tillamook lighthouse, ninety-one feet 

 above low water, was broken by a spray-propelled rock weighing 

 135 pounds. On the other hand, cUfFs made of hard rock, or that 

 slope gently into the water, can stand up to the sea for long periods 

 and show few signs of change. The coastal cUffs of Cornwall, for 

 example, show traces of beaches cut during an interglacial period 

 about a hundred thousand years ago, but we must remember that 

 sea level was higher then, and it has not been at its present level for 

 long. 



Where the rocks are soft, as in Holderness and East Anglia, 

 England, erosion carves the edge of the sea much more rapidly. We 

 have only to look along the Holderness coast to see that the cliffs 

 are retreating at an average rate of nearly six feet a year in places ; 

 several villages once Lining the coast were completely swept away by 

 the sea. Old records show that farther south, in Lincolnshire, in 1 2 8 7, 

 St. Peter's church at Mablethorpe was "rent asunder by the waves 

 of the sea." More recently, at the end of January 1953, strong 

 northerly winds caused a piUng up of water in the southern part 

 of the North Sea, and at high tide the effect was devastating in 

 Lincolnshire and Essex. The flooding here was particularly serious 

 because the land behind the sea walls, even in normal times, is well 

 below high-tide level. Several centuries ago this land was reclaimed 

 from the sea when sea level was about three feet lower, but today 

 the coastal area is entirely dependent for its defense against the sea 

 on sea walls, except where the natural protection of a wide, high 

 beach and well vegetated dunes survive. During the 1953 storm 

 surge these walls were overtopped and breached by the power of 

 the storm waves. The sea rushed in at a level 7.8 feet higher than 

 the predicted high tide, sweeping far inland and carrying along 

 tons of beach sand. Where there were high dunes and a lot of sand 

 on the beach, the storm waves spent their energy by moving the 

 sand instead of attacking the sea walls. 



In some areas erosion has been caused artificially. Leeward of 

 the breakwater built in 1929 at Santa Barbara, Cahfornia, serious 

 loss of land, extending ten miles down the coast in a few years, 

 resulted from the interception of the normal beach drift. The 

 cutting of an artificial channel through a barrier at Thyboroen in 

 west Jutland in 1825 also resulted in prolonged erosion. Natural 

 erosion is severe along part of the Baltic coast of Poland. Here 

 longshore drift removes sand in both directions from the beach, 

 and the weak cliffs, no longer protected from the waves, are driven 

 back at a rate of up to six feet a year; only one wall of a monastery 

 built in the fourteenth century, about one and a quarter miles 

 from the sea, now remains. Erosion in this area is speeded up by 

 extra high sea levels raised during periods of storm. 



Along the Suffolk coast, where there are low cliffs of sand and 

 gravel, erosion during the night of storm cut a forty-foot-high cliff 

 back forty feet, while another cliff only six feet high was driven 

 back ninety feet. But such rates of erosion occur only under very 

 unusual conditions. Even so, parts of the coast of East Anglia are 



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