Formation of a ribbon lake

Before

• snow accumulates in north facing hollows when more snow falls in winter than melts in summer.

• north facing slopes are more shaded so snow lies longer with accumulated snow compressing into ice

• the glacier moves downhill due to gravity/weight

During

• plucking occurs when ice freezes onto bedrock, pulling loose rocks away from the sides, making them steeper.

• abrasion is when the angular rock embedded into the ice grinds the base making it deeper.

• former interlocking spurs may be cut off by the glacier as it flows downhill leaving truncated spurs and deep valley sides

After

• ribbon lakes can form where softer bedrock is eroded more deeply than the surrounding area

• ribbon lakes can form where a terminal moraine creates a dam

• lake windermere is an example of a ribbon lake