COASTLINES GLOSSARY – GCSE Constructive Waves ­Smaller waves which are long in relation to their height. They have a strong swash and weak backwash, causing erosion Destructive Waves ­High waves with strong backwashes, which break frequently and cause erosion Corrosion/Abrasion­ Sandblasting effect of rocks carried in the waves being bashed against cliffs Hydraulic Action ­Air and water forced into cracks in the rock by the action of waves breaking pieces of rock away Attrition ­Process where rocks are broken down and smoothed by Bay­ Area of less resistant rock which forms an indentation on coastline Fetch­ Distance waves travel and wind has blown which affects strength/ size of waves Wave Cut Notch ­Knick cut into a cliff face at the point waves reach at high tide Wave Cut Platform ­A gently sloping area of flat rocks caused by erosion. Exposed at low tide Cave­ An area which has been hollowed out by the waves at the bottom of a cliff Arch­ An opening through a headland caused by the processes of erosion Sea Stack ­A piece of rock left standing, having been broken away from a collapsed arch Stump­ Remains of a stack after further erosion and collapse, only visible at low tide Boulders­ Rolling Traction: rolling of large rocks along the sea bed Saltation ­Movement of rocks in the sea by short jumps Suspension ­Movement of smaller material in the sea, previously held in the water Solution­ Very tiny material dissolved in the sea water Longshore Drift­ Movement of material along the coastline Swash­ Movement of waves up the beach Backwash ­Return of waves, back down the beath Beach­ Area of eroded material deposited on coastline Spit ­A long ridge of sand and shingle, attached to the land, ending in the open sea. Formed by deposition Bar ­Area of sand and shingle deposited just off the coast, often at river estuaries Tombolo ­A sand bar, attached to the coast at either end, enclosing a lagoon Salt Marsh­ Area of tidal marsh, often found behind a spit Marram Grass­ Pioneer species of grass that can tolerate salt Groynes­ Sea defences that protrude out to sea to collect sand and reduce erosion Armour Blocks/ Rip­Raps­ Large, interlocking man­made boulders which protect the coast Revetment ­Sloping concrete wall laid along the coast for protection Sea Wall ­Concrete wall built along the coastline to protect from sea action Offshore Breakwater ­Concrete wall located in the sea below low water mark to absorb the force of waves
Coastal Protection Scheme­ Scheme managed by local councils, maybe incorporating several coastal defences Berms­ Ridges of sand and shingle deposited on a beach Gloup/Blow hole­ Hole or vertical pit from surface to a cave where the wave can push up spray into the air by compressional force