Why do fjords have steep cliffs?
Show answer & explanation
Answer: Glaciers carve U-shaped valleys
Ocean waves erode cliffs — Wrong. Waves erode coastlines, but fjords form from glacier erosion. Glaciers carved deep valleys with steep walls; when ice melted, seawater flooded them.
Volcanic explosions carve valleys — Wrong. Fjords aren't volcanic. They're drowned glacial valleys—glaciers carved deep U-shaped troughs that filled with seawater after the ice age.
Glaciers carve U-shaped valleys ✓ — Correct! Fjords are glacial valleys flooded by the sea. During ice ages, massive glaciers carved U-shaped valleys with steep sides. When glaciers melted, rising seas flooded these deep valleys. Norway's fjords reach 1300m deep! The characteristic straight, steep-walled profile shows glacial erosion, not river valleys (V-shaped).