Strange patterns appear on lake in Iceland

The mysterious pattern is a rare phenomenon called 'finger rafting'

Updated: 

A strange phenomenon has taken over this frozen lake in Iceland, making it look like a scene taken straight from the X-Files.

Lake Thingvallavatn, Iceland's largest lake, has some local residents freaking out after a strange zig zag pattern appeared on it.

See also: 'Ice jams' form on Danube river in Hungary

See also: Mysterious ice circles appear in Washington river


The photos shared on the Thingvellir National Park's Facebook page show the pattern appearing on the ice sheets, which according to a park official, had never been spotted before.

But turns out this isn't actually a sign of alien activity, there's a confusing scientific explanation for all of this.

The mysterious pattern is a very rare phenomenon called 'finger rafting'.

This happens when thin ice sheets floating on water collide and push over and under each other alternately, creating what scientists describe as 'fingers'.

18 weird natural phenomena around the world

18 weird natural phenomena around the world