You can see pictures of the recent flooding here.
It’s a sad situation for those affected, but it’s nothing new. On the 7th of January, 1928, The River Thames burst its banks and flooded many parts of central London. It happened just after midnight while people were asleep so they had very little time to react. Fourteen people lost their lives and thousands of people, predominantly those from the poor slum areas, were left homeless.
Read about the the 1928 flood here.
There is now a flood defense constructed across the River Thames called the Thames Barrier which can be used to protect London against flooding caused by tidal surges coming up the river from the North Sea.
I remember visiting a church situated on the coast, not far from Cardiff, with my parents when I was a kid which had been flooded in the past. It was a long time ago and I don’t remember which church it was, though it is most likely one of two, either Peterstone Wentlooge or St Brides Wentlooge. Both churches have plaques which mark the level to which flood water rose during the Great Flood of 1607.
The reason I remember the day trip is because my mother said she could see the ghosts of people in a corner of the church, trying to escape from the flood water. My mother saw ghosts on various occasions, and was always very calm, as if it were a normal experience.
I remember once when we were on holiday in Southern Ireland, in a field where my father and I could only see a herd of cows, my mother could see people dressed as Quakers burying someone. The owner of the farmhouse where we were staying confirmed that the field had been used in the past as a Quaker burial ground.
I sometimes have premonitions; maybe it is something I have inherited from her. The night before the Twin Towers collapsed after being hit by planes in the notorious terrorist attack, I dreamt that I had to go to hospital and have both my legs amputated. The dream was so vivid, that on waking, the first thing I did was to check that my legs were still attached to the rest of my body. Luckily they were. Later when I saw the two towers collapse I realised that my legs were a symbol in the dream for the twin towers.
Was it a coincidence or was it a premonition? Usually when I dream I forget the details immediately on waking up, usually when the dream is linked in some way to something which then happens in the immediate or near future I can remember every little detail of the dream for years to come.
The flood is recorded as having occurred on the 20th of January 1607, however, there is some confusion over this date because between 1155 and 1751, our New Year began on the 25th of March, and so at the time of the flood the 20th of January would still have been in 1606, not 1607.
Also, at that time England and Wales were using the Julian calendar, introduced at the time of Julius Caesar, which did not quite fit with the seasons in that, although it had a leap year, it did not miss the leap year every century. The present Gregorian calendar was also adopted in 1752 by replacing the 2nd of September with the 14th of September, thereby losing 13 days. So using our present dating system the flood occurred on the 7th of January 1607.
Curiously there is still a small valley in Pembrokeshire, Wales that sticks with the Julian calendar and still celebrates New Year on the 13th of January.
The flood is recorded in 6 pamphlets, which were the means of distributing the news at the time. Just as is the case nowadays there was a tendency to not let the facts get in the way of a good story, so some exaggeration has to be accepted. But generally it is agreed that flooding occurred on both sides of the Bristol Channel severely affecting Cardiff, creating an inland sea of some 200 square miles and leaving about 2000 people dead.
There are flood marks in 6 churches: Kingston Seymour in Somerset on the English side, at Nash, Goldcliffe and Redwick upstream of Newport, and at St Brides Wentlooge and Peterstone Wentlooge between Cardiff and Newport on the Welsh side.
Conventional thinking is that the flooding was caused by a very high sea level; however, there is another theory that suggests the flood was caused by a tsunami. What is not in doubt is that there was actually an extremely high tide on the day and at the time the flood commenced
There have been two tsunamis known to have affected the UK. Some 7000 years ago the East coast of Scotland was hit by a tsunami generated by an undersea landslide off the Norwegian coast, and on the 1st of November 1755 an 8.7 magnitude earthquake occurred between Portugal and Madeira, its epicentre being about 300km offshore. It destroyed Lisbon and created a tsunami which caused more casualties than the earthquake, bringing water levels 10m above normal high tide level. The wave reached the coast of Cornwall in England where it was some 3m high.
The tidal range in the Severn Estuary/Bristol Channel is the second highest in the world, at Cardiff it is 13.4m, and it increases as one goes up the channel to over 14m at Bristol. So water levels of 8m above mean sea level are very likely and possibly up to 10m should a surge coincide with a high spring tide. Such a coincidence has happened more than once over the last couple of months.
Surges are caused by a combination of low pressure, which raises sea level, and wind which pushes the sea surface particularly into a constriction thereby raising water levels. Hence there are large surges in the Severn, Liverpool Bay and the southern North Sea where the Dover Straits act as a constriction.
So where does the Tsunami idea come from?
This was a theory put forward by a Professor of Geography at Bath University who was working with another professor from Woolangong University in Australia who has researched Tsunamis in the Indian and Pacific Oceans. They describe their big breakthrough as being a comment in one of the pamphlets that the wave was like "millions of thousands of arrows having been shot, and of such smoke as if the mountains were on fire".
The man from Woolangong says he has had reports that sparks are reported as coming off the top of Tsunami waves, or the crests sparkling, which he claims to be very strong evidence for a Tsunami, however, he doesn’t explain the reason for such a phenomenon.
Other evidence for it being a Tsunami put forward by them is that at Dunraven Bay and Sully Island they found boulders from rocks at the lower part of the shoreline higher up the shore, which they claimed could only have been moved by a tsunami wave not by a normal storm, particularly given the manner in which they were deposited. They also claimed erosion high on Sully Island could only have been caused by a tsunami wave.
They found a layer of shelly, sand, within the mud deposits at Rhymney Great Wharf which they said must have come from the deeper ocean as the Severn Estuary sediments are muddy and that this layer could only have been deposited by a Tsunami.
A man at Uphill, near Clevedon, said that in a storm surge flood that occurred in 1981 the water advanced across his garden at a fast walking pace, whereas the 1606/7 flood pamphlets describe a wave of water advancing at such a pace that it could not be outrun. None of the pamphlets spend much time describing the weather as stormy, though they do mention it as such. One mentions sunny weather. So the conclusion by the tsunami proposers is that a surge is less likely.
But a tsunami must have a cause. So what caused the Bristol Channel Tsunami?
There is no evidence of an undersea landslide. The researchers interviewed Dr Roger Musson at the British Geological Society (BGS) in Edinburgh, who specialises in research into historical Earthquake and seismic hazard. He agreed that there was a fault to the south west of Ireland on which an earthquake of 4.5 magnitude has been recorded. So this was claimed by the researchers to be the likely trigger for the tsunami.
However, there are flaws in their argument. First of all there is the lack of any reason for the sparkling of the water to be confined to a tsunami wave. There is no evidence as to when the rocks at Dunraven Bay and Sully Island were moved, or whether they were moved in a single event. And the erosion at Sully Island probably originates from prehistoric times and general weathering.
There was a known tidal surge at the time which also affected the East coast of the U.K. The presence of sand in the deposits at Rhymney Great Wharf can be explained by them washing in from the Estuary during a flood.
So why did the water rush in so fast in 1606/7 when it only trickled in 1981?
In 1981, the seawall remained intact. If the seawall, which is basically an earth bank between 3 to 4m high in most places, had failed, the water would have flowed through at a great rate. Prior to the reign of Henry VIII (1509 - 1547) the levels on either side of the Estuary were owned by Monasteries which maintained the sea defences. It is believed that the defences were less well maintained after the dissolution of the Monasteries by Henry VIII, and so failures probably occurred which explain the onrush of water. That would have certainly washed in sand from the Estuary.
The parallel is the disastrous flooding on the East coast of England, Holland and Germany in 1953 following the Second World War when again flood defenses had been allowed to deteriorate.
According to Roger Musson, any large earthquakes tended to be recorded, especially in ecclesiastical records, as they would have damaged buildings such as churches which were the largest and most expensive buildings at the time. He believes there may be quite a complete historical record of British earthquakes from medieval times. An Earthquake that damaged Lincoln Cathedral in 1185 is recorded; however, there is no hint of any significant earthquake in 1606/7 that could have caused a tsunami. Nor does there appear to be any other record of a tsunami wave hitting the coastline of Britain, Ireland or France in 1606/7, one would have expected widespread damage from such an event.
So there you have it, Tsunami or not, that the flood occurred is not in doubt.
I am indebted to Hugh, family friend and mah-jong partner, for his extensive contribution to this article.
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