Monday, 3 June 2013

Thursday 6th June - How Britain became an Island

How Britain became an island
Dr. Jenny Collier, Imperial College, London
Megaflood events involving sudden discharges of exceptionally large volumes of water are rare, but can significantly affect landscape evolution, continental-scale drainage networks and climatic patterns. In this talk, Dr. Collier will present a new regional bathymetric map of part of the English Channel derived from high-resolution sonar data, which shows the morphology of the seabed in unprecedented detail. These data image a large bedrock-floored valley that contains a distinct assemblage of landforms, including streamlined islands and longitudinal erosional grooves, which are indicative of large-scale subaerial erosion by high-magnitude water discharges. The data support a megaflood model, in which breaching of a rock dam at the Dover Strait instigated catastrophic drainage of a large pro-glacial lake in the southern North Sea basin. It is suggested that this event permanently isolated Britain from mainland Europe and prompted a large-scale reorganization of river drainage patterns across northwest Europe. In turn these consequences significantly influenced the patterns of early human colonisation of Britain.
BRLSI, 16 Queen Square - 7.30 p.m. free refreshments. 
Everyone welcome - £4 for visitors
Details about the Bath Geological Society can be seen on the website.

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