* Astronomy

We already know that Britain can be affected by tsunamis: one hit our shores as recently as 1755, when a massive earthquake reduced Lisbon in Portugal to smoke and rubble. The quake sent a wave charging across the Atlantic and into the English Channel, travelling as fast as a modern aeroplane and hurling giant slabs of rock from the sea bed far up the beach at Lamorna Cove in Cornwall. But the professors say that wasn't a unique event; in fact, they claim we have experienced an array of tsunamis, and, for the past 300 years, they have struck once every century.

Source

The Great Flood of 1607

Four hundred years ago	on 20th January 1607, 9.00am. A massive wave devastated the counties of the Bristol Channel, UK. It came without warning, sweeping all before it.
	Dr Ted Bryant The flooding stretched inland as far as the Glastonbury Tor. Two hundred square miles of Somerset, Devon, Glamorganshire and Monmouthshire were inundated, and up to two thousand people died. Historians have usually attributed the flooding to a storm but new geographical research, by Dr Ted Bryant of the University of Wollongong in Australia has shown that it was more likely to have been a tsunami. According to contemporary accounts, the flood occurred rapidly in apparently good weather on 20th January 1607 for about nine of the morning, the same being fayrely and brightly spred, many of the inhabitants of these countreys prepared themselves to their affayres when they saw mighty hilles of water tombling over one another in such sort as if the greatest mountains in the world had overwhelmed the lowe villages a description closer to a tsunami than a storm.
From their fieldwork	Flooding of the coast line they have estimated that the tsunami would have been at least 5.5m high when it struck the Somerset coast, travelling at a speed of 32mph, and penetrating inland as a moving wave for at least 2½ miles from the shore. These results are consistent with the description of mighty hilles of water and others that the wave is affirmed to have runne . with a swiftness so incredible, as that no gray-hounde could have escaped by running before them. However, the historical accounts tell us that the waters reached the foot of Glastonbury Tor some 14 miles inland where it flooded alms houses - this is possible as the ground in the Somerset Levels slopes landward, so that when the tsunami wave broke and collapsed the water rushed further inland rather than return to the sea.
The accounts	Bristol Channel contain a long list of Somerset places that were badly affected, including Berrow, Yatton, Puxton, Congresbury, Kingston Seymour, Worle, Kewstoke, Banwell, Wick, Weston-Super-Mare, Uphill, Kenn, Combwich, Burnham, Lympsham, East Brent, Mark and Brean, the latter four are said to have been swallowed up by the wave with 26 fatalities recorded at Brean.
	Flooding at Brean Amongst the Brean victims, a John Good lost his wife, five children, and nine servants as the wave struck, but he saved himself by clinging to thatch that carried him for more than a mile before it washed up on a bank. Thatch seems also to have saved the wife and son of a John Stowe of Berrow, upon which they were washed two miles by the wave to safety; he was not so lucky and drowned with three of his other children. At Bridgwater, two villages near theirabouts and our market town overflown [by the wave] and report of 500 persons drowned, besides many sheep and other cattle.
	Bristol Channel At Kingston Seymour a plaque in the church commemorates the event: an inundation of the Sea-water by overflowing and breaking down the Sea banks; happened in this Parish of Kingstone-Seamore, and many other adjoining; by reason whereof many Persons were drownd and much Cattle and Goods, were lost: the water in the Church was five feet high and the greatest part lay on the ground about ten days.
	Flooding The water lay on the ground for such a long time partly because of the landward slopes of the ground, and probably because all the sluice-gate keepers had perished.
Apart from the historical accounts	Deep sea active fault and the field evidence, the evidence that confirms that the 1607 flood was caused by a tsunami is that a previously overlooked contemporary account states that an earth tremor was felt on the morning in question. It is most likely that an active fault system offshore southern Ireland had a significant earthquake that created the tsunami. Indeed, the fault in question has apparently experienced a magnitude 4.5 earthquake in 1980, not big enough to cause a tsunami, but indicates that it may have been able to produce a bigger one in the past. Ongoing research will establish the frequency of earthquakes and tsunami that have struck the Somerset coast through time.
What has happened before could happen again,	Deep sea shell found inland and the low-lying areas are now more populated than in 1607, so casualties could be higher. But for a tsunami to have any impact on the Somerset coast the tsunami must arrive close to high tide, because the tide goes out so far in the Bristol Channel, if the tsunami arrived at low tide it might not reach the shore, let alone flood the land. The 1607 event shows that these unfortunate coincidences do occur and for this reason the Bristol Channel coast, as well as all coasts everywhere, should be protected by a tsunami warning system.
	Without such a warning system, people living in low-lying coastal areas should go upstairs, or climb a tree, if they feel an earth tremor or see the sea rise or rush out suddenly, as research has shown that many stone buildings and trees withstand all but the biggest tsunami. Stay up off the ground for at least a few hours as it is likely that more than one tsunami wave will strike, the second or third wave often being higher than the first.
A primary source	Gods Warning for the Great Flood was written by John Paul, the Vicar of Almondsbury on 26th January 1606: "But the yeere 1606, the fourth of K (King) James, the ryver of Severn rose upon a sodeyn Tuesday mornyng the 20 of January beyng the full pryme day and hyghest tyde after the change of the moone by reason of a myghty strong western wynd. So that from Mynhead to Slymbryge the lowe groundes alongst the ryver Severne were that tuornyng tyde overflowen, and in Saltmarsh many howses overthrowne, sundry Chrystyans drowned, hundreds of rudder cattell and horses peryshed, and thowsandes of sheep and lambs lost. Unspeakable was the spoyle and losse on both sydes the ryver. [..cut..] The salt water was in Rednyng in Sansoms new chamber to the upper stepp save twoo, and in Hobbes house syx foote hyghe. In Ellenhurst at Wades howse the sea rose neere 7 foote and in some howses there yt ran yn at one wyndow and out at an other. [..cut..] Also in Brysto by credyble report that mornyng tyde was hygher than that Evenyng tyde by nyne foote of water. John Paul, Vicar of Almondsbury, 26th January 1606"
Note:	The flood occurred around 9am on the '20th January 1606', although in the modern calendar this is the 30th January 1607. This reflects the different dating convention before calendar reform in 1752. In 1606/7, the legal year began on March 25th. This means that December 1606 was followed by January 1606, and 1607 didn't start until the end of March. However,the idea of a Christian year starting on January 1st (anno domini) there also existed , rather than the legal year, so some records may refer to the 'legal' January 1606 as January 1607.
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-- Edited by Blobrana at 19:57, 2007-07-27

Four hundred years ago, in the reign of James I of England, a disaster hit the south west of the country, as a huge surge of water coursed up the Bristol Channel - covering 200 square miles of land with water and killing 2,000 people.
Eyewitness accounts of the great flood of 30 January 1607 tell of "huge and mighty hills of water" advancing at a speed "faster than a greyhound can run" and only receding 10 days later.
The flood reached a speed of 30mph and a height of 25ft. It swept up to four miles inland in the Bristol area, north Devon, Pembrokeshire, Glamorgan, Monmouthshire and Cardiff - and up to 14 miles inland in low-lying parts of Somerset.

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