A video circulating on social media shows what looks like a clear division between the Pacific Ocean and the Atlantic Ocean, with descriptions claiming that the two oceans meet but don’t combine. This erroneous claim emerges quite regularly online but has a simple scientific explanation.

"The waters meet without mixing,” reads the caption on this video, which has been posted in English, French, Spanish and Italian. Just one post in English got more than 172,000 views. Most of the posts say that the video shows the meeting point between the two oceans. In the video, there’s a clear demarcation between two bodies of water, visible because of their distinct colours.

The same video has also been said to show where the river Congo meets the Atlantic Ocean, or even the dividing line between the Mediterranean Sea and the Atlantic.

How do you identify the video's origin?

The one thing all these videos have in common is that the video quality is mediocre – and it is likely that a better-quality version of the video exists somewhere on the internet.

But we cannot find the original video simply by doing a reverse image search (click here to learn how to do an image seach). The false information has been shared so many times that there are now hundreds of variations on the same post.

So to find the original video, we have to start with the process of elimination: Find the first time this video appeared online. To do this, click on "Tools" at the top of your Google search, then "Time" and then click on a "Custom range" date period.

By using this tool, we can narrow down the results year by year – and if you go back to 2015, you can see that there are only two results for that year, one of which is a YouTube video.

This clearer, better-quality video published online in July 2015 shows exactly the same scene. Entitled, "When the river meets the ocean," it indicates that it was taken on the Fraser River in British Columbia in Canada. Maryan Pearson, who posted the video, says she took it when she was aboard a ferry between Duke Point and Vancouver. So it doesn’t show either the Atlantic or the Pacific Ocean.

What explains the strange sight?

This case is similar to a photo published in 2015 that claimed to show the exact spot where the Pacific and the Atlantic meet.

Photo taken by Ken Bruland, a researcher at the University of California in Santa Cruz, in 2007.

The photo was actually taken in 2007 by Ken Bruland, a researcher at the University of California, Santa Cruz, who was studying the phenomenon in the Gulf of Alaska. He explained why it happened in an article by the debunking website Snopes. He told Snopes that this is what occurs when glacial rivers, carrying lots of sediment, flow out into oceans.

“Once these glacial rivers pour out into the larger body of water, they’re picked up by ocean currents, moving east to west, and begin to circulate there.”

He says that it’s not true to say that the two bodies of water aren’t mixing. The border between one type of water and another is always moving, sometimes disappearing completely according to the level of sediment in the water and other factors.

So while the photos and videos are real, they don’t actually show something that astonishing or unusual, nor do they show a static "border" between two oceans.

Video showing the same phenomenon where the Gulf of Mexico meets the Mississippi River.