Individuals who live in low-lying coastal areas such as Ringsend in Dublin and parts of Cork and Galway have been advised to pay particularly close attention to any flood warnings from next month, as tides here prepare to reach their highest level in almost 20 years.
According to the Marine Institute, this year the country will experience a period of "unusually" high tidal ranges.
These will peak in Galway around October 8th, and in Dublin around September 10th. The differences in dates are explained by mitigating local factors linked with the effects of the Irish Sea and the open Atlantic. However, significant flooding is only expected to occur if the period of high tides also coincides with a "storm surge", leading to onshore winds that drive water ashore and low atmospheric pressure.
As a result, Dr John Joyce of the Marine Institute said anyone living in low-lying areas should monitor three-day weather forecasts and pay attention to any flood warnings. "We know these high tides are going to occur. To put it in perspective, the actual increase is only 10 centimetres above the norm. So the only real danger is if we have a storm surge."
Twice a year, at the spring and autumn equinoxes, the equatorial plane of the earth is aligned with the orbital plane around the sun. As a result, the biggest spring tides occur. But the particularly high spring tides predicted for September and October are explained by a "nodal cycle". This relates to the tilt of the moon and the "elliptic" nature of the moon's orbit around the earth.
The "nodal cycle" occurs once every 18.6 years, and allows for an extremely big tide to occur during this cycle.
Predicted high tide levels in Dublin on Sunday 10th of September are a high of 4.58 metres above the baseline at 4.58am. In Galway on October 8th, tides are expected to be some 5.64 metres above standard baseline figures at around 5.40pm.