We recently came across this article about a floating island in Argentina that rotates. Producer and film director Sergio Neuspiller discovered it when filming in the area and has since started a Kickstarter to raise funds to investigate it further. See the Kickstarter promotion video below:
The island is visible in Google Earth imagery and has been in existence since at least 2003, the date of the oldest Google Earth image of the location. Here is an animation showing how it moves over time:
It is fairly obvious what is happening (no, it’s not an alien base as some have suggested). When you have a floating island and a water current that flows along one side of it, it will naturally rotate and become circular over time, as well as carving out a circular hole. The phenomenon is quite rare, because the conditions must be just right. Floating islands of plants are themselves quite rare, but in addition, it requires a current, though a fairly slow moving one.
[ Update: We believe wind may be the main factor in some instances rather than current. ]
There is a special type of floating island that is very common and that is ice. The phenomenon does occur with ice, as you can see in the YouTube videos below:
We tried to find other examples of rotating floating islands not made of ice and we found one on a lake in India:
Read more about it here.
We also found a reference to one in the Okavango delta. You can read the full story about it in a PDF found here. Apparently a Brian Wilson discovered a rotating floating island and identified it in aerial imagery from as far back as 1944. It could be seen to have kept rotating up until about 1974, when it attached itself to one side of the lagoon it was in and remained there until at least 1990. We had a look at the coordinates given and not far from that location did indeed find a floating island that has moved between 2006 and 2016. We cannot positively confirm that it is the same island.
But for the real treasure trove of rotating floating islands, the place to go is the Luapula River on the border of Zambia and the Democratic Republic of the Congo (DRC). Sadly, there isn’t a lot of historical imagery, so good animations were not possible. So, we are showing them in the form of ‘before and afters’ to demonstrate that the islands do, in fact, move.
A round one, an oval and another shape, sharing a pool.
If we are not mistaken, the dark patches are fire scars, suggesting the island can sustain fires without destroying it.
A whole bunch of floating islands!
And that’s just some of them. There are many more! Amazingly, we could just (although only just) see some of them moving using our Landsat animations KML file.
To see the above locations in Google Earth, including historical imagery tours, download this KML file.