• 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.
What is the Moon wobble?
• 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.
What impact does this wobble have on Earth?
• The moon wobble impacts the gravitational pull of the moon, and therefore, indirectly influences the ebb and flow of tides here on the Earth. In fact, as per the NASA study, 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: A double whammy situation:
• 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!
Mains Paper 3: Science and Tech
Prelims level: Moon wobble
Mains level: Impact of Moon wobble