Formation of a ribbon lake

before

formation of the glacier

snow accumulates in north-facing hollows due to more snowfall in winter than melting in summer.

north facing slopes are more shaded so snow lies longer and compresses into neve then ice.

before

Glacier Movement

the glacier moves downhill due to gravity and weight.

during

Plucking

ice freezes onto bedrock, pulling loose rocks away from the sides, making them steeper

during

Abrasion

abrasion occurs when angular rocks embedded in ice grind the base, making it deeper

during

spurs

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

after

how ribbon lakes form

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

An example of a ribbon lake

Lake Windermere