Physical geography definitions

• Stack - pillar of rock left when an arch collapses
• Salt marsh - deposited mud in sheltered areas behind a spit
• Headland - hard rock sticking out into sea
• Hydraulic power - waves hitting the cliff
• Abrasion - sand paper effect of pebbles by waves
• Attrition - rocks knocking into each other and breaking into smaller pieces
• Corrasion - rocks being hurled at the cliff
• Solution - sea water and chemicals cause rock to dissolve
• Traction - large pebbles rolling on seabed
• Saltation - pebbles bouncing on seabed
• Suspension - particles carried in the water
• Solution - dissolved chemicals in water
• Deposition - dropping off of material when the flow of water slows
• Wave refraction - bending of the wave to mirror the coastline
• Slumping - rapid mass movement of a whole section of cliff down a saturated slope or line of weakness
• Groynes - timber or rock structures built out to sea
• Sea wall - concrete wall at the foot of the cliff
• Rock armour - piles of large boulders dumped at the base of the cliff
• Gabions - wire cages filled with rocks