‘Supertides’ raise flood alerts in London and around UK

Widespread threat of coastal flooding has continued this week as a rare astronomical alignment has produced larger than normal tides around the country’s coasts.

Environment Agency flood alerts currently remain in place for areas along the River Thames, and several other areas around the UK.

These so-called ‘supertides’ occur when the alignment of sun, moon and Earth create a larger gravitational pull on the sea, occuring once every 18 years. The tide levels are mostly only a few centimetres higher than normal, but the presence of low pressure and strong winds, as has been observed this week, can greatly enhance flood risk.

In March 2015, unusually high tides led to flooding of embankments along the Thames. Further ‘supertides’ are predicted to occur in September 28 and October 27 this year.