ice stream
/ˈʌɪs striːm/noun
1A stream of floating sea ice driven by a current or the wind in a particular course; especially that moving with the Labrador Current.
2A gradual flow of ice on land, as in a glacier; specifically (in recent use) a flow of faster-moving ice within an ice sheet, especially in Antarctica.
Origin
Early 19th century. From ice + stream.