How do earthquakes trigger landslides and rockfalls on mountainsides?

Earthquake shaking can cause slopes to fail almost instantly if the rock is already cracked or unstable. Loose soil may also lose strength through liquefaction, especially if it is waterlogged, making hillsides behave like a fluid. The 2008 Sichuan earthquake in China triggered thousands of landslides across a vast mountainous region. Earthquake-induced landslides can block rivers, damage roads, and create dangerous temporary lakes. Hazard maps often combine slope angle, rock type, rainfall, and seismic risk to identify vulnerable areas.