Archaeologists investigated the Outer Thames Estuary seafloor to find out what it can tell us about the past. They discovered evidence of ancient landscapes and shipwrecks, lying deep below the waves. 

To collect information archaeologists use a variety of geophysical survey and sediment sampling techniques that are also used by geologists and ecologists, including collecting sediment samples using a vibrocorer.  Marine geophysicists who specialise in archaeology assess the geophysical survey data collected during the REC surveys.

The Outer Thames Estuary REC Archaeological Results

This section provides a summary of the Outer Thames Estuary REC results for the archaeological research.

Click on links below to find out about each topic, or scroll down to read the entire text.

You can find out more about the scientific research techniques mentioned in the text by visiting our “How we study seafloor” webpages.

Read our Sustainability webpages to discover how the results will help protect the Outer Thames Estuary REC area. 

Did you know that people once lived on the Outer Thames Estuary seafloor?

One of the key tasks for the REC archaeologists was to assess the potential for finding prehistoric evidence within the sediments beneath the seafloor.  To do this they need to understand how the climate changed over the past million years.

Understanding past climate change

 During the last 2.5 million years, known as the Pleistocene on the geological timescale, there have been numerous cold periods, called ‘glacials’ separated by warmer periods called ‘interglacials’. Archaeologists are particularly interested in the last one million years when our ancestors are known to have occupied Britain.

During the cold phases, large continental ice sheets covered much of Britain and most of the north-west European peninsula. 

During warm periods the sea-levels were similar to those today and Britain was an island. However, during cooler periods, when water was locked up in ice sheets, the sea-level was lower than today. Britain was not an island, but a peninsula joined to continental Europe. During these cooler times, our early ancestors were able to occupy large parts of the peninsula, now submerged beneath the sea.

At the end of the last glaciation, around 12,000 years ago, the climate became warmer so people could live on the peninsula. Then, as the glaciers melted, the sea level rose and gradually flooded many places where people had lived. Geologists refer to the past 10,000 years as the Holocene.

Watch our film to see how the coastline of Britain changed over the last 20,000 years.

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This means that in the past people could live in the Outer Thames Estuary REC study area. However, what evidence do we have that they did?

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Prehistoric climate change timescale



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Discovering Britain’s prehistoric past

Archaeologists use a variety of techniques to explore what evidence for the prehistoric past remains hidden on and below the Outer Thames Estuary seafloor. 

Seafloor archaeological evidence dates to the Palaeolithic and Mesolithic periods of prehistory. Check out our Prehistoric Climate Change timechart above to see how they fit into what happened during the Pleistocene and Holocene.

During past excavations on the coast of the nearby mainland, very close to the Outer Thames Estuary REC, archaeologists discovered Palaeolithic stone hand-axes, as well as many other stone tools. The earliest evidence found shows that people were living in this area over 900,000 years ago. 

Marine geophysicists examined the geophysical survey data for features such as river channels cut and then filled with seafloor sediments during the Pleistocene and Holocene. Preserved within such deposits you can find environmental remains, such as seeds and animal shells. By studying the environmental remains discovered in vibrocore samples of the infill deposits, archaeologists could build a picture of the vegetation of this past landscape.

This work enabled the mapping of the ancient paths of the River Thames and Medway, which extended beyond today’s coastline.  As people need water to live, features like these old rivers are useful places to start looking for archaeological evidence for Britain’s prehistoric past.

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Finding ship and aircraft wrecks

Since ancient times, boats have been used for transport, trade, and to fight wars. Archaeologists assessed the potential for discovering archaeological evidence for these activities in the Outer Thames Estuary.

As Britain is an island, boats and ships play an important role in everyday life.  Using the National Monument Records and the United Kingdom Hydrographic Office records, archaeologists identified 1,533 shipwrecks in the Outer Thames Estuary. These shipwrecks date from 1320 AD to the present day, and range in type from small fishing vessels to grand cargo sailing ships, and even World War II submarines.  Although there are no records of older shipwrecks, it is possible that some will be discovered in this area in the future.

Most known shipwrecks date from the 19th century to the present day. This is because they are constructed primarily from metal so they preserve better underwater, they are easier to find, and a record is usually kept somewhere that they sank. 

Older, less substantial ships or boats may not preserve well, or become buried under the seafloor over time.  In addition, there may not be any historical record of their demise.  If you explore the Outer Thames coastline, it is possible you may discover clues about the maritime activities of the distant past.

The archaeologists looked at evidence along the coast for different periods and discovered a long maritime history dating back to the Iron Age, in 800 BC. For example, the old Roman port town of Felixstowe is close to the study area. It is therefore possible that we will discover Roman shipwrecks off this coast.

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New Discoveries

The REC results identified seven new possible ship or aircraft wreck sites within the Outer Thames Estuary study area.

The geophysical survey images of the seafloor showed several anomalies that the archaeologists interpreted as possible shipwrecks

Often, these small lumps, as you can see on the survey image on the right, indicate a wreck on the bottom of the sea. 

From these images, it is often difficult to say it is definitely a wreck, never mind confirm whether it is a ship or plane.  It could simply be an unusual outcrop of bedrock. Archaeologists are experts at identifying when a lump is more than a bit of rock.  However, when funding is available, divers will check out and positively identify these possible wreck sites.

Other sources of information studied by the archaeologists, for example the National Monuments Record, did not have a record of these sites. This means the geophysical survey has given us new information about the maritime history of this area.

The geophysical survey covered only a small percentage of the large Outer Thames study area. This means that there may be lots more wrecks for us to discover in this region.

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