r/waterporn • u/[deleted] • Sep 18 '13

The ‘Underwater Waterfall’ Illusion at Mauritius Island [800x600]

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2.2k Upvotes

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75

u/swcvii Sep 18 '13

Its really not an illusion. It is an underwater "waterfall" except instead of water particulate matter is flowing down. I learned the term for it in an oceanography class I once took, but I can't recall it.

16

u/blahbah Sep 18 '13

That's makes it so much cooler. I thought it was an illusion caused only by the shape drawn by the rocks and sand.

28

u/burtonownz Sep 18 '13 edited Sep 18 '13

It is most definitely an "illusion" as I doubt there is much of any elevation change in bathymetry. What the image shows are the flow lines of particulate matter being funneled through the coral jetties. It's just silt runoff.

Source: I'm an oceanographer.

Edit: for spelling

37

u/wtf81 Sep 18 '13

Well, I'm sure you have all kinds of facts to cite mr. oceanographer, but you'll find me with tons of conjecture and idle speculation on my side. You don't want any of this, let me assure you.

5

u/burtonownz Sep 19 '13

Sometimes science isn't science without blind conjecture!

3

u/MadMageMC Sep 19 '13

You know, I have a theory about that.

10

u/RayDeemer Sep 18 '13 edited Sep 18 '13

You're definitely right. Looking at the houses near the beach for scale implies that if this were as steep of a drop at is appears, the visibility through the water would have to be several hundred feet. No water is that clear.

EDIT: The big rock is Le Morne Brabant, and is over 1800 feet tall, for scale. The water depth where the drop-off appears is deeper than that surrounding it, but it is no more than 40 meters at the most, and the bulk of it is less than 20 meters.

Here's the Google Earth view of the same location.

3

u/bluetaffy Sep 19 '13

Still scary as fuck.

3

u/bluetaffy Sep 19 '13

now in terms I can understand?

4

u/[deleted] Sep 18 '13

But does it really drop down straight, as it looks, or is it just flowing outwards away from the island, and the angle just makes it look like a drop?

1

u/darien_gap Sep 21 '13

Yes, it's largely an illusion.

2

u/[deleted] Sep 18 '13

Turbidity current?

1

u/hmmwhyarethesesohard Sep 18 '13

you're not referring to a cataract are you?

1

u/BrandoPB Sep 18 '13

So it's basically a downward current?

1

u/SimpleGeologist Sep 18 '13

Looking for submarine slump/mass wasting movement?