Historic tsunami in Britain since AD 1000: a review

摘要

The British coast is not considered at particular risk from tsunami, a view that is supported by a number of recent government reports. However, these reports largely ignore some written historic records that suggest southern Britain has experienced a number of events over the past 1000 yrs. This study briefly assesses these records and recognises four groups of events: 1) sea disturbance and coastal floods in southeast England linked to earthquakes in the Dover Straits (e.g. 1382 and 1580), 2) far-field tsunami reaching the coast of the British Isles, for example, from earthquakes along the Azores-Gibraltar Fault Zone offshore Portugal (e.g. 1755), 3) tsunami associated with near-coastal low magnitude earthquakes (e.g. 1884 and 1892), and 4) a flood event in AD 1014 that has been linked to comet debris impact. The seismogenic events range from minor water disturbance, through seismic seiching, to small and 'giant' waves, suggesting near-coastal, low-magnitude, shallow earthquakes may be capable of triggering disturbance in relatively shallow water, as supported by similar occurrences elsewhere, and that the British tsunami risk requires a more careful evaluation.