A strudel /ˈstruːdəl/ (plural: strudel) is a vertical hole in sea ice through which downward jet-like, buoyancy-driven drainage of flood water is thought to occur. This feature is less than a few tens of meters in size and typically occurs within 30 km from a river mouth, in the sea ice expanse that is fastened to the coastline (known as fast ice). Once the water that flooded the ice has completely drained off the ice surface, strudel become recognizable by a radial pattern of feeder channels that lead to the hole. They are elongated and irregularly spaced, with the larger ones up to several kilometers apart. Their distribution tends to be controlled by weak areas in the ice – in places, they line up along fractures or refrozen extensional cracks. The ice sheet where they occur may be 2 m