Generally, a tsunami is caused by an earthquake near the shore or underwater. Normal tsunamis usually originate from offshore earthquakes, submarine landslides and undersea volcanic activity, and range from barely perceptible waves to walls of water up to 300 feet high. a b c BBC staff (24 September 2014). "The great flood of 1607: could it happen again?". BBC Somerset . Retrieved 20 February 2008. His words give a fascinating insight into the flood and how it impacted the city. What was Bristol like in 1607?

Rev Seyer’s description also gives a hint of the movement of the water - this wasn’t just a gradual rising tide, but a wave.Experts have warned that a mega-tsunami could put coastal towns across the UK at risk in the future. The event could happen at any time with as little as just six hours' warning, an expert has said, however chances of one happening in the near future seem pretty slim. Long, Dave (2017). "Cataloguing tsunami events in the UK". Geological Society, London, Special Publications. 456: 143–165. doi: 10.1144/SP456.10. S2CID 134094076.

They were the early forms of sensational journalism, and often written to a particular end. The writers with the most motive for telling and re-telling the story of the Great Flood were those with a religious axe to grind. It saw a loss of life on a single day that probably outstripped the worst of the Bubonic Plague, and on a scale not seen until the Nazis began the Bristol Blitz. Carroll shows how ignorance (of science), fear and greed led to blaming people who acted or looked a little different for everything that was wrong in this society. By accusing those less fortunate or less powerful and creating public spectacles, many influential men were able to turn the public gaze away from their dubious land-grabbing, economic and expansionist tendencies. Professor Simon Haslett (left) and Dr Ted Bryant (right) proposed the theory that the 1607 flood in the Bristol Channel was due to a tsunami (Image: John Christie) An earlier 2002 research paper, following investigations by Professor Simon Haslett of Bath Spa University and Australian geologist Ted Bryant of the University of Wollongong, suggested that the flooding may have been caused by a tsunami, after the authors had read some eyewitness accounts in the historical reports which described the flood. [9] [10] [11] The British Geological Survey has suggested that, as there is no evidence of a landslide off the continental shelf, a tsunami would most likely have been caused by an earthquake on a known unstable fault off the coast of southwest Ireland, causing the vertical displacement of the sea floor. [12] One contemporary report describes an earth tremor on the morning of the flood; [13] however, other sources date this earthquake to a few months after the event. [14]A number of historical documents exist that describe the event and its aftermath. An area from Barnstaple in north Devon, up the Bristol Channel and Severn Estuary to Gloucester, then along the South Wales coast around to Cardigan was affected, some 570 km of coastline. It rose five feet at Trin-mille. At its return it brought great trees down the river, but did no harm to the bridge.” Contemporary accounts of the flood were written by people such as the Puritan pamphleteer, William Jones: On 30 January 1607, around noon, the coasts of the Bristol Channel suffered from unexpectedly high floodings that broke the coastal defences in several places. Low-lying places in Devon, Somerset, Gloucestershire, and South Wales were flooded. The devastation was particularly severe on the Welsh side, extending from Laugharne in Carmarthenshire to above Chepstow in Monmouthshire. Cardiff was the most badly affected town, with the foundations of St Mary's Church destroyed. [ citation needed]