Have you seen one of Britain’s spectacular natural phenomena, the Severn Bore? It is a large surge wave that occurs in the estuary of the River Severn, where the tidal range can be as much as 15 metres. The estuary is shaped in such a way that the water is funnelled into an increasingly narrow channel as the tide rises, thus forming a large wave. As the width of the river rapidly decreases, so does its depth, thus forming a funnel shape. As the incoming tide travels up the estuary it is squeezed into an ever decreasing channel and the surge wave, or bore, is formed. The wave travels upstream for roughly 22 miles until it reaches Gloucester.
The Severn bore has become very popular with surfers, with the largest biggest 4 and 5 star bores occuring in conjunction with large spring and autumn tides. The bore is best surfed on a nine to ten foot longboard – the extra buoyancy and length are necessary when attempting to surf a tidal wave. If surfing is not for you, the bore also attracts a lot of spectators, eager to watch the spectacle as the bore travels past.
For Severn bore times and more information visit http://bit.ly/severnbore
Photo credit: cc-by-sa/2.0 – Surfing the Severn bore by Jim Nicholls geograph.co.uk/p/379254
