TIL: Weird Double Whirlpool Systems Sail Across The Australian Seas

in steemstem •  last year  (edited)

Do you remember this week's phenomenon post on whirlpools? Like we said on Monday, whirlpools are spinning water vortexes that appear when two opposite moving sea currents (tidal flows) meet in an area with the "perfect" morphology (narrow passages made by straits or rocks on the seabed). Although whirlpools and eddies are not a rare phenomenon, spotting two of them joined in a U-shape form, spinning at the opposite direction one another at the same time is something rare and unique! [2, 3, 6, 7]

Image from: wikipedia.org - Author: Walter Baxter - License: CC BY-SA 2.0 

Across the oceans whirlpools and eddies often show up, mixing up the waters, transferring nutrients and warmer water masses towards the poles and almost always travelling westwards. These spinning vortexes were theoretically believed to appear in pairs ever since 1970, but it was not until recently (late 2017) that scientists from the University of Liverpool did spot not one, but nine such pairs, called modons, by analyzing satellite data. The paper (Geophysical Research Letters) was released on December 4th, 2017. The paper was "inspired" by a pair of modons observed in the Tasman Sea (between Australia and New Zealand). [2, 3, 4, 6, 7]

The irony in this is that satellites have been recording their movement for at least 25 years now, but nobody ever noticed them until now. Looking back in satellite images from 1993, scientists saw eight modons around Australia and one in the Atlantic, at the southeast of Africa. [3]

What are modons?

Typical eddies move usually westwards at speeds of 1-2 cm/sec (not as fast as you might have imagined). Modons have the ability to travel almost 10 times faster than a typical eddy and cover distances of even more than 1,000 km. They can last for about 6 months before splitting up and gradually die off. [2, 3]

Eddies "travelling" along coastal areas may meet up with friction because of the coastline. This leads to another mass of water starting to spin in the opposite direction. The bottoms of the two whirlpools will then join in U-resembling shape and the couple will live together for a few months, enjoying a cruise over the planet's oceans. Another idea for a modon formation is that two whirlpools meet in the ocean, collide and become entwined. But both ideas need further studying before deciding which one is true. [8]

They are thought to be the ocean equivalent to smoke rings. Oceanographer Chris Hughes (one of the leading scientists of the study) referred to them as "half a smoke ring". He also thinks that a modon's high speed might be the result of the balance between the two eddies, which could possibly explain why the modons move eastwards instead of westwards. [5]

Smoke ring?

A smoke ring is a circular vortex of smoke (read more on wikipedia). Modons are an aquatic equivalent of a smoke ring. They are actually called half smoke rings because the eddy system forms half a circle, as the other half is cut off by the surface of the water. [9]

Image from: wikipedia.org - Author: Traitor - License: CC BY-SA 3.0 


Eddies stir up the ocean waters, transferring nutrients and changing the temperatures of the oceans, as they bring warmer water towards the poles and then colder waters towards near the equator latitudes. They are even thought to "transfer" marine life from one area to another. [2, 4, 7]

As beneficial as they might be, eddies "feed" deeper waters, since they bring valuable nutrients for the phytoplankton; they can cause damage as well. Oceanographer Glen Flierl (University of Massachusetts) underlines indications that eddies crashing on the continental shelf might "srap off" zooplankton and fish larvae, which leads to a marine life population decline. [7]

You can have a watch of these videos, to learn more about pool modons (weird name, isn't it?).


[1] agupubs.onlinelibrary.wiley.com
[2] popsci.com
[3] sciencealert.com
[4] gizmodo.com
[5] azula.com
[6] aol.com
[7] newsweek.com
[8] valuewalk.com
[9] news.liverpool.ac.uk

Thank you so much for your time!

Until my next post,
Steem on and keep smiling, people! 

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Thanks. Upvoted and has been added to the latest MAP Upvotes post.

Much appreciated! Thank you! :)

Nice expansion on the whirlpool topic. Plus its something I never heard of before :)

However, the word "modons" is kind of lame compared to something like "Malestrom!" The hydrologists that discovered this could have come up with a better name I think.

Now we've gotta find an instance of three whirlpools.

Thank you @tking77798!! :)

I agree, modons are not a kick-ass name! Those hydrologists were not very creative.

Do you think a triple system would be possible? It would definitely be fascinating nonetheless :)

I think it's a cool name! Reminds me of mastodons. It has a villainy sound to it. A "Lord Modon" wouldn't be out of place in Game of Thrones.

I am grinning from side to side right now. The name "modon" isn't really the only non-kick ass name here. Even the word Eddie has a comic ring to it. This sorta bears out the quality of an antithesis, you know, Modon is a villian, Eddie is a clown. It's like our scientists have a pretty bad sense of humor. Anyway, humor or not, this whirlpool thingy is a pretty wonderful natural phenomenon, and the write up too does justice to it. Nice one here @ruth-girl.

How bout a superhero movie where some evil guy named Eddie Modon, whose supervillain name is, fittingly, 'Whirlpool', goes against Deadpool? Which pool will win?

I'm laughing hard at this!!! 🤣🤣🤣🤣

Honestly? When I read the word modon I thought of Austin Powers and his mojo

You remind me of the time when comedy movies were actually funny.


Oh my! Oh my! Eddy is a lame name, but never really made the clown connection. It turns out this phenomenon is weirder than I thought :P

Thanks @funmiakinpelu! :)

Lovely article!

Plus, I had all kinds of poetic conclusions to that last video. There are fewer explanations and more visual examples in that one (compared to the first by the same person), allowing the mind to sort of wander off...

Thank you! :D

Well, observing nature makes your imagination go wild, who can argue with that?

Never knew whirlpools could be so romantic! (Like the opposite of foul-mouthed Deadpool.)

Many interesting bits here, a whole hidden world I wasn't aware of.

I can't wait to try the pool thing! That looks almost like magic. So simple! Why doesn't every kid know about this?

Aha! They seem to be romantic wanderers of the seas... With their joined "tails", just like those cute seahorses, those modons in love cross the seas in search of cozy nest to house their love...

I didn't know that pool trick either! Do you think it could work in one of those inflatable children's pools? 'Cause that's the best I have at home :P
Tell us if it works when you try it (a video post would also be a nice idea) ;)

That's really interesting! I had no idea about their vertical nature. I had to deal with air bubble rings (fancypants term is toroidal vortices) and had no idea they could be stable as half rings or oriented that way.

Bubble rings? Great! Now I'll have to watch some videos of those too!!
only this time I made sure to reply first and then open a new tab for youtube :P

Wow! This is so weird. Mother Nature is full of weird and bizarre occurrences.

P.S: {And unrelated question} When are you gonna write something on Bermuda triangle? :)

Cool, isn't it??

Hmm, I don't know. I think I should put it on my list ;)

Cool, isn't it??

Sure, it's very cool :)

Wow! This half ring thing is super cool. Idk why in my entire life i never thought of them, lol. :D
Additionally u gifted a subscriber to physics-girl channel. :D

Thank you!
And I believe physics-girl thanks you too :P

hehe. its a pleasure! :)

That's amazing, I had no idea!

Imagine a drone shooting such a unique "cruise"

If global warming does cause the world's oceans to heat up, are phenomenon like whirlpools and modons likely to be affected? You talked about a couple of ways they benefit the ocean ecosystem, I have read some of these systems are more delicate than we might expect.

From what I was reading yes, the extra heat will affect such phenomena and probably make them more intense.

Beautiful work @ruth-girl
Your posts are worth the wait
Good morning

Thank you! Have a nice day too!

Your article always amazing! Thanks for sharing! Keep it up and waiting for new article

Thank you for reading! :)

  ·  last year Reveal Comment

Nice spammography
The flag is on the house :)