Lake Michigan has formed thousands of ice shards as spring begins to melt the frost caused by a polar vortex.
The lake in the US Mid West has been frozen for most of winter after sub-zero temperatures hit parts of the US including Michigan and Illinois.
During the peak of the polar vortex, temperatures fell to minus 30C in the Michigan area, which caused the formation of ice shelves on the lake as waves froze over the icy surface.
With the arrival of spring, the ice shelves are beginning to thaw, leading to sheets of ice breaking and forming shards on the surface of the lake.
Water is moving underneath the ice and pushing shards up to the surface, captured in photos from the pier of South Haven, Michigan.
The photos show broken ice piling up into thousands of individual layers.
The US Coast Guard has warned the patterns should only be viewed from safe spots like piers or dry land, as the ice is not safe to stand on.
The moving water underneath the ice means it is easy to fall through as the surface breaks up.
US Coast Guard spokesman Grant Heffner told MLive.com: “No ice is safe ice, especially this time of year. The ice is certainly deteriorating and breaking up.”
In late January, temperatures plunged as low as minus 30C in parts of the US, with a strong wind chill caused by the polar vortex.
Governors in Wisconsin, Illinois and Michigan declared emergencies as the worst of the cold threatened.
Before spring arrived, 56% of Lake Michigan – which borders Michigan, Wisconsin, Illinois and Indiana – was covered in ice.