Coastal towns are braced for the highest ‘super tides’ in 19 years as a rare set of astronomical forces align.
Sea levels are expected to be 50cm higher than a normal spring tide this week as a so-called Supermoon – when the Moon is at the closest part of its orbit – combines with an alignment of the Sun, Moon and Earth to create a perfect storm of cosmic forces.
Tides are governed by the gravitational pull of the moon and, to a lesser extent, the Sun.
Because the Sun and Moon go through different alignment, this affects the size of the tides.
Tidal forces are strengthened if the moon is closest to Earth in its elliptical orbit and when the Sun and Moon are directly over the equator.
The Moon’s orbit takes it over the equator every 27.2 days and the Sun reaches the same point twice a year, at the spring and autumn equinox.
This week these events have coincided with the two bodies aligning on the same side of the Earth – further magnifying their gravitational pull – and Moon being at the closest point of its orbit.
But, despite the highest ‘astronomical’ tide for 19 years, no coastal flood warnings have been issued as high pressure should protect the UK from high water.
Weather can have an even greater effect on sea levels than astral bodies.
Strong winds can pile up water on coastlines and low pressure systems can also cause a localised rise in sea level.
In pictures: Super Blood Moon
In pictures: Super Blood Moon
The supermoon rises behind Glastonbury Tor in Somerset, England
The super moon rises above Brighton, England
A full moon silhouettes television and radio antennas on Boutilier Mountain, in Port-au-Prince, Haiti
A super moon rises in the sky near the Eiffel tower as seen from Suresnes, Western Paris, France
A flock of birds fly by as a perigee moon, also known as a super moon, rises in Mir, Belarus, 95 kilometers (60 miles) west of capital Minsk, Belarus
A supermoon rises over a minaret of a mosque in Wadi El-Rayan Lake at the desert of Al Fayoum Governorate, south west of Cairo, Egypt
The moon rises through the mist of the north east coast ahead of a lunar eclipse
A partially eclipsed supermoon, the last of this year's supermoons, rises over Las Vegas, Nevada
The supermoon is seen in Bogota, Colombia
The supermoon, prior the beginning of a total lunar eclipse, in Bogota, Colombia
A perigee full moon is seen during a total lunar eclipse behind The Colorado State Capitol building in Denver, Colorado
A supermoon, is seen next to the Empire State Building in New York City
A blood moon rises behind a hilltop residence in Solana Beach, California
The moon appears behind the monument at the San Nicolas church in Cali, Colombia
The moon enters the maximum eclipse in Glastonbury, England
A swollen 'supermoon' bathed in the blood-red light of a total eclipse is seen in Strasbourg, eastern France, early on September 28, 2015
The Super Blood Moon rises over a sailboat in Boston Harbor on September 27, 2015 in Boston, Massachusetts
The moon turns red during a total eclipse, seen behind the iconic Liver Bird on the Liver Building in Liverpool, north west England, early on September 28, 2015
Rising over the Lower Fox Creek School near Strong City, Kan
The Supermoon above the Notre-Dame de la Garde basilica in Marseille
An estimated 2,800 properties – from East Anglia to Somerset - were flooded in December 2013 after the weather created a storm surge.
Watch the video below for Nasa's explanation of why the spectacle happens:
High pressure this week means wind levels should low and high pressure will effectively push down on the sea, driving down tide levels.
John Curtin, the Environment Agency’s interim executive director of flood and coastal risk management, said: “The flood risk is low over the next few days. Some of the highest spring tides of the year start this weekend but as we are not expecting any unsettled weather, it is unlikely that this will lead to flooding of coastal locations.
“The Environment Agency is monitoring the situation closely alongside the Met Office and local authorities, and will issue flood alerts and warnings if required.”Reuse content