Polyniya
Polyniya is a place where sea ice breaks open, and the sea surface appears.
Polyniya caused along the coastline when winds blowing from land to sea push ice away from the coast are called Coastal Polyniya. On the other hand, the Polyniya that occurred in the Wendell sea in the 1970's were located in the center of the Wendell sea, so obviously were from a different cause. Around the poles, there is highly salty, relatively warm water below the surface layer, and convection between this water and the surface layer is thought to be a cause for this second kind of Polyniya.