On the southwestern point of Mauritius is a crazy-looking phenomenon. When viewed from the air (either in real life or in Google Earth) it appears to be an underwater waterfall!
Of course, a real underwater waterfall isn’t possible but the actual answer is really quite fascinating. An article on ScienceBlogs.com really digs into it, but the short version is:
What you’re witnessing, that looks like an underwater waterfall, is actually sand from the shores of Mauritius being driven via ocean currents off of that high, coastal shelf, and down into the darker ocean depths off the southern tip of the island.
To see it for yourself, check out the full article on ScienceBlogs or grab this KML file
to fly there in Google Earth. [NOTE by Frank: Although Google has 3D bathymetry (underwater terrain), they don’t attempt to provide such data so close to shore. Also, I checked a nautical chart, and the area is not as deep as it appears (only 10-20 meters). So, the effect is an optical illusion. But, it does look cool!]
About Mickey Mellen
Mickey has been using Google Earth since it was released in 2005, and has created a variety of geo-related sites including Google Earth Hacks. He runs a web design firm in Marietta, GA, where he lives with his wife and two kids.
“Of course, a real underwater waterfall isn’t possible…”
Not so hasty!
http://en.wikipedia.org/wiki/Denmark_Strait
“The world’s largest waterfall, an underwater waterfall in this case, flows down the Western side of the Denmark Strait, known as the Denmark Strait cataract. It is over three times higher than Angel Falls in Venezuela.”
A better / more direct link:
http://en.wikipedia.org/wiki/Denmark_Strait_cataract
Been watching QI?
Yes! I’m trying to find a link to the episode, but no luck.
Found it… Here it is:
https://www.youtube.com/watch?v=HvY-hBK1cnY
Starts at 32mins 10 secs.
Nice to know what is really going on, but none of the facts presented here makes swimming here any less scary.