Dunkirk transgression

North Sea Periphery, c. 250–c. 500: High Water Levels and a generally cooling climate. Source: Higham's Rome, Britain and the Anglo-Saxons (ISBN 1-85264-022-7, 1992).

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.[1][2] Conditions remained favourable until 250 AD, and the region became densely populated.[3][4]

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, c. 350–c. 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);[5] Friesland;[6][7] Groningen;[8] Ostfriesland, German Friesland and the Weser/Jade estuary;[5][8] and Dithmarschen, Eiderstedt and Nordfriesland.[9][10]

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.[11] Zones with river clay were so regularly deposited with alluvial silt that habitation was almost impossible between the years 250 and 650.[12]

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).^[citation needed]

See also

• Roman Warm Period, which lasted to about 400 AD/CE
• Anglo-Saxon settlement of Britain – Cultural and population changes in England c. 450 to 630 AD
• Frisii – Germanic tribe

References

1. Louwe Kooijmans 1974:44–45, The Rhine/Meuse Delta.
2. Ejstrud 2008:17–19, The Migration Period.
3. Knottnerus 2001:30–31, LANCEWAD 2001: Cultural History.
4. Meier 2004:55, 63, Man and Environment in Schleswig-Holstein.
5. Louwe Kooijmans 1974, The Rhine/Meuse Delta, PhD Thesis.
6. Louwe Kooijmans 1980:106–133, Archaeology and Coastal Change in the Netherlands.
7. Nienhuis 2008, Environmental History of the Rhine-Meuse Delta.
8. Knottnerus 2001:29–63, Cultural History in LANCEWAD: Landscape and Cultural Heritage in the Wadden Sea Region—Project Report.
9. Meier 2004:55–70, Man and environment in the marsh area of Schleswig-Holstein from Roman until late Medieval times.
10. Meier 2013, Landscape and Settlement History of the North-Sea Coast of Schleswig-Holstein.
11. Louwe Kooijmans 1974:44, The Rhine/Meuse Delta.
12. Louwe Kooijmans 1974:120, The Rhine/Meuse Delta.

Works cited

• Ejstrud, Bo (2008). The migration period, Southern Denmark and the North Sea : a workbook in relationship to the Gredstedbro find. Esbjerg: Maritime Archaeology Programme, University of Southern Denmark. ISBN 9788799221417.
• Knottnerus, Otto S. (2001). "The Wadden Sea. A unique cultural landscape" (PDF). Lancewad (12). ISSN 0946-896X.
• Louwe Kooijmans, L. P. (1974). The Rhine/Meuse delta. Four studies on its prehistoric occupation and holocene geology. Leiden: Leyden University Press. hdl:1887/27971. ISBN 978-90-60-21194-6. OCLC 1095248.
• Louwe Kooijmans, L. P. (1980). "Archaeology and Coastal Change in the Netherlands". In Thompson, Frederick Hugh (ed.). Archaeology and Coastal Change: Being the Papers Presented at Meetings in London and Manchester on 27th October and 5th November, 1977. Society of Antiquaries of London. ISBN 978-0-500-99031-5.
• Meier, Dirk (January 2004). "Man and environment in the marsh area of Schleswig–Holstein from Roman until late Medieval times". Quaternary International. 112 (1): 55–69. Bibcode:2004QuInt.112...55M. doi:10.1016/S1040-6182(03)00065-X.
• Meier, Dirk (January 2013). "From nature to culture: landscape and settlement history of the North-Sea coast of Schleswig-Holstein, Germany". Landscapes or Seascapes?. Comparative Rural History of the North Sea Area. 13: 85–110. doi:10.1484/M.CORN.1.101549. ISBN 978-2-503-54058-0.
• Nienhuis, P. H. (2008). Environmental History of the Rhine-Meuse Delta: An ecological story on evolving human-environmental relations coping with climate change and sea-level rise. Springer Science & Business Media. ISBN 978-1-4020-8213-9.

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 PDF