This weekend Auckland will experience a King Tide — an unusually high tide that arises from the combination of gravitational factors.
All tides depend on changes in the moon’s gravitational pull as the moon revolves around the Earth. The sun also plays a role, so during a full moon or a new moon, when the sun and moon are lined up, higher than normal tides called “spring tides” occur. When a spring tide occurs while the moon is at its closest to the Earth, the extra strong gravitational pull results in a very high tide called a “king tide”.
This weekend’s king tide is expected to peak on Saturday morning, at 10:05 a.m. on the east coast and 12:12 p.m. on the west coast.
A king tide also occurred in February last year, and I headed down to my local beach with my camera to check it out. Plenty of people were had already enjoying the beautiful summer’s day at the beach, but there was precious little space for them to set up on the sand. In fact, I could only find about 1 square metre of sand on the entire beach that hadn’t been drenched by the incoming waves. One enterprising woman had built a moat and wall to protect her towel from the oncoming water.
The little estuary at the southern end of the bay was completely flooded too. By the time I was ready to leave, about 50 minutes after the king tide, the tide had dropped just enough for the estuary to start streaming back into the ocean, and the pull in that little river was pretty damn strong!
King tides aren’t just a nuisance for beach-goers who are trying to keep their towels dry. Elsewhere in Auckland, low-lying roads and coastal parks get flooded. More importantly, these events give us some idea of what a future with higher sea levels may be like. The King Tides Initiative aims to document the effects of king tides happening now and to raise awareness about the future impacts of climate change on our daily lives. (You can head over to their Facebook page to check out some much more dramatic pictures than mine!)
While humans have a tendency to fight encroaching water and coastal erosion with sea walls, doing so can be an expensive — and ultimately futile — endeavour. Auckland architect, urban designer, and climate change adaptation specialist, Bernd Gundermann, believes we’re better off helping communities build resilience by learning to live with the encroaching water. In many cases, the best course of action may be letting the ocean reclaim the land.
In the context of my own little beach, I can’t decide whether I feel more sorry for the beach-goers who won’t have any beach left to go to between low tides, or the landowners whose front lawns may begin to disappear under the relentless onslaught of the waves. What do you think?