Context

• Sometimes, the moon seems to move in mysterious ways. It is mostly circles and ovals. But there is also something else — a so-called wobble — animating those rotations and revolutions. According to a recent study, the phenomenon is expected to lead to more flooding here on Earth in the middle of the next decade.

About

• The moon wobble is nothing but a regular swaying in the moon’s orbit.
• It was first documented way back in 1728.
• This wobble takes over an 18.6-year period to complete, and continues in a cyclic fashion.

Impact

• The moon wobble impacts the gravitational pull of the moon, and therefore, indirectly influences the ebb and flow of tides here on the Earth.
• Each wobble cycle has the power to amplify and suppress the tides on Earth.
• One half of the 18.6-year cycle suppresses the tides, which means that the high tides get lower, while the low tides get higher than normal.
• Once this cycle completes, the situation flips—in the subsequent cycle, the tides are amplified, with high tides getting higher and low tides, lower!
• The lunar cycle is expected to shift again by mid-2030, and in the coming phase, the tides will amplify once again.

Moon wobble and climate change

• The upcoming changes in the lunar cycle will pose a serious threat, as the amplified high tides coupled with the rising sea levels will make the risk of flooding far greater across all coastal regions of the globe.
• The study predicts that the high tide-associated floods—also known as nuisance floods or sunny day floods—may occur in clusters that could last for months or even for longer periods!

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