Meteotsunamis (displacements due to atmospheric pressure, rather than seismic shock) are somewhat more common, especially on the southern coasts of England around the English and Bristol Channels.
The area is believed to have had a coastline of lagoons, marshes, mudflats, and beaches, and may have been the richest hunting, fowling, and fishing ground in Europe at the time.
Although there is no record of the overall death toll, the 19th-century French writer Arnold Boscowitz claimed that "great loss of life and property occurred upon the coasts of Cornwall".
[7] The tsunami also reached Galway in Ireland, at a height of 2 m (6.6 ft), and caused some serious damage to the "Spanish Arch" section of the city wall.
[8] On 20 July 1929 a wave reported as being between 3.5 and 6 m (11 and 20 ft) high struck the south coast of England including busy tourist beaches at Worthing, Brighton, Hastings and Folkestone.
[9][10] A small tsunami in the English Channel with a peak wave height anomaly of 40 cm (16 in) occurred on 29 June 2011 affecting four counties on the south coast of England; Cornwall, Devon, Dorset and Hampshire.
William of Malmesbury stated that "A tidal wave... grew to an astonishing size such as the memory of man cannot parallel, so as to submerge villages many miles inland and overwhelm and drown their inhabitants."
[15] A witness stated that at 09:15, the sea in Pegwell Bay, East Kent, "suddenly receded about 200 yards (180 m) and returned to its former position within the space of about 20 minutes".
In the 1990s, geologists realised that the Cumbre Vieja volcano in La Palma, in the Canary Islands off North Africa, could pose a tsunami risk to Britain and Ireland, as it is seemingly unstable.
They concluded that a future volcanic eruption will result in the mass of rock alongside the volcanoes breaking off and falling into the sea as a massive landslide.