Dunkirk Transgression

The Dunkirk transgressions were tidal bulges or other sea level-related marine transgressions (risings), often heightened by river floods, affecting the North Sea and adjoining low land. Most of this land is vulnerable to such events being below or approximately at sea level. Three events and mass evacuations, at least, are seen, some stretching to land above-sea level today. The events affected the Low Countries and other land near the German Bight, Thames Estuary and The Wash. They spanned from the late Roman period until Early Medieval Europe.

Outline knowledge

The exact scale of each event with notable human impact in duration, being hypothetically determined, is debated. The cause of each is also somewhat debated, however tidal bulges have been a continuing cyclical problem of the North Sea in the centuries since.

Chronology

The main parts of the Low Countries were lightly populated until about 200 BC, when the climate and environment became more amenable to human habitation. Conditions remained favourable until 250 AD, and the region became densely populated.

Fens below sea level were highly vulnerable to a tidal bulge until great dams and sea walls were built as shown in the North Sea flood of 1953. A series of marine transgressions followed (in specialist academic literature called Dunkirk 0 through to Dunkirk IIIb) characterised by a rising water table and floods that left layers of clay on the land. The heaviest blow came with the "Dunkirk II transgression" that began in the 3rd century and continually worsened, leaving such low land uninhabitable,  350– 700 CE. People were forced to abandon their homes and emigrate. Archaeologists find evidence for this across the Rhine/Meuse delta (Zeeland, Brabant, parts of South Holland and Limburg);, ''The Rhine/Meuse Delta'', PhD Thesis. Friesland; Groningen;, ''Cultural History'' in LANCEWAD: Landscape and Cultural Heritage in the Wadden Sea Region—Project Report. Ostfriesland, German Friesland and the Weser/ Jade estuary; and Dithmarschen, Eiderstedt and Nordfriesland.

Across the Rhine/Meuse delta, the population became scant. Between the 5th and 7th centuries there were few centers of population there, and in the estuarine and peat areas no settlements have been found. The area would not be repopulated until the Carolingian Era. Zones with river clay were so regularly deposited with alluvial silt that habitation was almost impossible between the years 250 and 650., ''The Rhine/Meuse Delta''.

Soil survey evidences and relative lack of human occupation artefacts leads scientists to theorise the Netherlands was largely underwater between the mid-third-century and 1050. This more narrow geographic range of depopulation covers the third Dunkirk Transgression period (alternatively suffixed ''III'').

See also

* Roman Warm Period, which lasted to about 400 AD/CE
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References

Works cited

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* {{cite book , last1=Nienhuis , first1=P. H. , title=Environmental History of the Rhine-Meuse Delta: An ecological story on evolving human-environmental relations coping with climate change and sea-level rise , date=2008 , publisher=Springer Science & Business Media , isbn=978-1-4020-8213-9 , url=https://books.google.co.uk/books?id=RQRdOc3iaHYC , language=en

External links

Sea level rise, transgression phases and storm surges in maritime Flanders to the end of the 16th century. A study of the landscape, ecology and climate from a historical point of view. Dr. Beatrijs Augustyn, (English summary of the general conclusion of the thesis by B. Augusyn, Zeespiegelrijzing, transgressiefasen en stormvloeden in maritiem Vlaanderen tot het einde van de XVIde eeuw. Een landschappelijke, ecologische en klimatologische studie in historisch perspektief, Brussel, Algemeen Rijksarchief, Studia 37-38), 1992
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Geology of the Netherlands
Geology of Belgium
Geology of France
Geology of England
Geology of Denmark
Geology of Germany