Polynya (redirected from polynyas)

Polynya 

an area of open water in the sheet ice of a river or in the floating ice fields of a sea or lake. Polynyas form in rivers where there is a rapid current or where groundwater seeps into the river. They also form in tail waters. In addition, they form where warm water from industrial enterprises is emptied into a river and at the source of a river that originates in a lake, where the ice is broken up by the river’s movement. This is characteristic of seas, where polynyas are formed primarily by the wind.