8 August 2014
King Tides, Sign of Sea Level to Come
King tides will occur along the Hawke’s Bay coastline through August 12-15 and provide a look into the future at
expected sea levels.
The very high tides next week will come well up on beaches and may flood low-lying facilities around the coast such as
Hawke’s Bay Trail pathways around Ahuriri Estuary and Clive River, and boardwalks in the Inner Harbour.
The term ‘king tide’ is the commonly used name for the highest tides that affect the coast. The scientific name is a
perigean spring tide, and they occur about 3 times a year. King tides occur when the moon is at its closest to the earth
(in its perigee) and there is a full moon, meaning the sun is on the other side of the earth increasing the
gravitational pull.
“There’s an international interest now in king tides because of climate change, as the higher tide is an indication of
what we can expect as normal tide levels in the future,” says Mike Adye, Group Manager Asset Management.
“While this may be decades away, the king tides can still affect us in Hawke’s Bay now if they coincide with a storm at
sea. The higher sea level with storm surge and wave action will cause erosion and damage to structures along the coast,
such as dunes, groynes and sea walls.”
The weather during this king tide is forecast to be settled.
ENDS