Flaw lead is an oceanographic

Oceanography

Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean...

 term for a waterway

Waterway

A waterway is any navigable body of water. Waterways can include rivers, lakes, seas, oceans, and canals. In order for a waterway to be navigable, it must meet several criteria:...

 opening between pack ice and fast ice

Fast ice

Fast ice is sea ice that has frozen along coasts along the shoals, or to the sea floor over shallow parts of the continental shelf, and extends out from land into sea. In Antarctica, fast ice may also extend between grounded icebergs...

. Flaw lead occurs annually at the time when central pack ice drifts from coastal ice, thereby creating the flaw. The process begins in autumn. Flaw leads can have interconnected polynya

Polynya

A polynya or polynia is an area of open water surrounded by sea ice. It is now used as geographical term for an area of unfrozen sea within the ice pack. It is a loanword from , , which means a natural ice hole, and was adopted in the 19th century by polar explorers to describe navigable...

s. The Canadian government's Circumpolar Flaw Lead System Study, through the University of Manitoba

University of Manitoba

The University of Manitoba , in Winnipeg, Manitoba, Canada, is the largest university in the province of Manitoba. It is Manitoba's most comprehensive and only research-intensive post-secondary educational institution. It was founded in 1877, making it Western Canada’s first university. It placed...

 examines the physical changes and their effects on biological processes with flaw leads.

A similar opening ("lead") can exist between pack ice and the shore

Shore

A shore or shoreline is the fringe of land at the edge of a large body of water, such as an ocean, sea, or lake. In Physical Oceanography a shore is the wider fringe that is geologically modified by the action of the body of water past and present, while the beach is at the edge of the shore,...

, referred to as a shore lead

Shore lead

A shore lead is an oceanographic term for a waterway opening between pack ice and shore. While the gap of water may be as narrow as a tide crack if closed by wind or currents, it can be as wide as . Its formation can be influenced by tidal action, or subsurface conditions, such as current and...

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