Flandrian sealevel changes in the Thames Estuary and the implications for land subsidence in England and Wales

CATASTROPHIC flooding occurred in the Lower Thames and lowland coastal areas of eastern England in 1953. Large-scale investment in port, freight, factory facilities and connected urban development, has centred in these littoral and coastal zones. The effects of changing sealevels, such as seen in 1953, could, therefore, cause even greater economic and human loss in the future, unless government expenditure on flood alleviation schemes, as exemplified by the Thames barrage project, is increased and a coordinated flood protection policy established. Information on the rate of changing relative sealevel in south-east England is thus of great value. (A description is given here of a stratigraphic study upon the interleaved Flandrian biogenic and inorganic deposits of the Lower Thames estuary, carried out between central London and the Isle of Grain (Fig. 1).) From this, the heights of relative sealevel movements were determined and plotted against time to show the rate of relative sealevel change and subsidence trends for the Thames and southern England. The vegetational and environmental history was deduced from pollen, diatom and other micro-fossil analyses, with radiocarbon dating applied to establish an objective chronology.