Some 300 meters off the coast of England’s southern county of Sussex sits the ruins of the medieval city of Dunwich – under 30 feet of water and silt. Once a thriving port city, great storms in the 1200s swept the city into the ocean as the Dunwich River upon which it sat was filled with silt, choking off its harbor. The city was eventually abandoned and the remains continued to be claimed by the sea as the coastline eroded.
In 2008 researchers at the nearby University of Southampton began a survey of the remains of the town and with the aid of new technology began to reveal a city once the size of today’s London city center known as the City of London, some 0.7 square miles. Surprised by how much of the old city survives, researchers are finding and mapping nearly intact streets and structures, including multiple commercial buildings and churches, with names such as Blackfriars Friary, the Chapel of St. Katherine and St. Peter’s Church which once sat on a high cliff overlooking the town. Another large structure near the city center seems to be some sort of town hall.
This should remind us of how suddenly coastlines can change, notes David Sear, the University of Southampton researcher in charge of the mapping study. The storms that devastated Duwich took place during a transition from a relatively warm medieval period into what climatologists call the “Little Ice Age” which took place from 1350 to 1850. In a statement, Sear noted that global warming has made coastal erosion a topic in the 21st century but that it has all happened before – with devastating results.
Coastal survey expert Peter Murphy with the group English Heritage notes that the loss of Dunwich is part of a long and inexorable process that points to more losses of coastal towns in the future.
Economic and social factors also impact what transpires when coastal communities fall prey to nature’s whims. “With the harbor filling with silt, the town partly destroyed and market incomes in decline, in the end people just gave up on Dunwich,” Sear explains.
Is this a portent of things to come in our day? While it seems impossible to imagine modern coastal cities underwater, it should be noted that all this took place in the age of animal transportation, long before the advent of fossil fuels.