THE CHANGING COASTLINE OF ESSEX 93
attack the cliff directly. Apart from the direct erosion
caused, it probably undermines the lower part of the cliff,
creating conditions conducive to slumping. It is not without
significance that the big slump in the Walton cliffs pre-
viously described occurred within a month of the storm surge
of November, 1897.
In the marshland fringed coast of the southern part of the
county, the occurrence of a storm surge invariably leads to
the inundation of vast areas of low-lying land. The protecting
sea walls vary in height from 11 to 15 feet above mean sea
level. A normal spring tide leaves a safety margin of
between 5 to 9 feet. With the additional rise of sea level
created by the surge, the lower parts of the sea wall may
be completely overridden. In the high tide of 1897 about
one third of Foulness Island was flooded, much of the wall
between Rugwood and Fisherman's Head being completely
demolished. The sea walls bordering the marshes of St.
Osyth, Mersea and Dengie also broke and let in the sea.
It is this never-ending struggle with the sea which has
characterised man's occupancy of the coastal area of Essex
for thousands of years. In the south of the county, sub-
aerial forces assist him, in the north they tend to work
against him.
REFERENCES.
Brown, E. (1927). An Essex Island Parish. Essex Review, 36. 170.
Doodson, A. T. (1929). Report on the Thames Floods, 1928. Met. Office-
Geophysical Mem. No. 47.
Johnson, D. W. (1919). Shore Processes and Shoreline Development. 325.
Redman, .J. B. (1863). The East Coast between the Thames and the Wash
Estuaries. Min. of Inst. of Civil Engineers, 23, 188.
Steers, J. A. (1946). The Coastline of'England and Wales, 390.
Whitaker, W. (1889). The Geology of London, 1, 478.
(1887). The Geology of the Eastern End of Essex.
Woodward, H. B. (1903). Victoria County History of Essex, 1, 22.
This paper was prepared and read at a meeting of the Club before the
disastrous floods of January 31st-February 1st, 1953. As in the case of
the earlier surges which have affected the Essex coast, the exceptionally
high tide was due to northerly winds associated with a deep depression
(968mb.) over the North Sea which piled up water in the southern North
Sea. The duration of the surge was longer than usual, for the depression,
instead of moving quickly eastwards over continental Europe, moved south-
east to the German Bight, thus maintaining the northerly winds for a
considerable period. (The meteorological conditions were similar to those
of the 1897 surge as given in Figure 8.) All parts of the east coast, there-
fore, experienced the surge for at least one culmination of high water.