A 'wobble' in the orbit of the Moon puts NASA on alert

07/25/2021 10:23 AM

• Clarín.com

• International

Updated 07/25/2021 10:45 AM

The terrible floods that hit Europe put the world on alert.

And especially to NASA, which warned that changes in the Moon's orbit could generate

major floods

on the planet in the next decade. 

Beginning in the mid-2030s,

aligning sea level rise with a lunar cycle

will see coastal cities begin a decade of dramatic flood increases.

That's the conclusion of the first study to account for all

known

oceanic and astronomical causes

of flooding, led by members of NASA's Sea Level Change Science Team at the University of Hawaii.

The experts' forecast

The new study shows that high tides will exceed known flood thresholds more frequently.

What's more, floods will sometimes occur in groups

lasting a month or more

, depending on the positions of the Moon, Earth, and Sun.

When the Moon and Earth are specifically aligned with each other and with the Sun

, the resulting gravitational pull and the corresponding response from the ocean can cause city dwellers to face

floods every day or every other day

.

"Low-lying areas near sea level are increasingly at risk and suffering from increased flooding, and will only get worse," NASA Administrator Bill Nelson said in a statement.

"The combination of the Moon's gravitational pull, rising sea levels and climate change will continue to exacerbate coastal flooding on our shores and around the world. NASA's Sea Level Change Team is providing crucial information so that we can

plan, protect and prevent damage to the environment

and livelihoods of people affected by the floods, "he added.

The gravitational pull of the Moon, rising sea levels, and climate change will continue to exacerbate flooding.

Photo: EFE / EPA

"It's the

cumulative effect

over time that will have an impact," said Phil Thompson, an assistant professor at the University of Hawaii and lead author of the new study, published in July in Nature Climate Change.

Thompson noted that because high tide flooding involves a small amount of water compared to storm surge, there is a tendency to view it as a less significant problem overall.

"But if it floods

10 or 15 times a month

, a business can't keep running with its underwater parking lot. People lose their jobs because they can't go to work. Leaky cesspools become a health problem. public, "he explained.

The wobble of the Moon and climate change

Why do coastal cities so far apart begin to experience these higher flood rates around the same time?

The main reason is a

regular wobble in the Moon's orbit

that takes 18.6 years to complete

.

There is nothing new or dangerous about this wobble;

It was first reported in 1728.

What

is

new

is how one of its effects on the gravitational pull of the Moon, the main cause of tides on Earth,

will combine with

rising sea levels as a result of global warming

.

In the middle of the Moon's 18.6-year cycle, Earth's regular daily tides are suppressed: high tides are lower than normal and low tides are higher than normal.

The Moon's "wobble" cycle lasts 18.6 years.

Photo: AFP

In the other half of the cycle, they are amplified: high tides rise and low tides fall even more.

Global sea level rise pushes high tides in only one direction: up.

So half of the 18.6-year lunar cycle counteracts the effect of rising sea levels at high tides and the other half

enhances the effect

.

The Moon is now in

the tidal

amplification

part of its

cycle

.

However, along most coasts, the sea level has not risen enough that, even with this lunar "push", high tides regularly exceed flood thresholds.

It will be a different story the next time the cycle amplifies the tides again, in the mid-2030s.

Europa Press.

Look also

More storms like Germany are forecast in Europe due to climate change

Like fireworks: the stunning images of nearby galaxies captured by the world's most powerful telescopes

Another business for Elon Musk: NASA chose SpaceX to travel to Jupiter's moon Europa