Coastal systems and landscapes - definitions Flashcards
What is a barrier beach?
A narrow, elongated sand ridge rising above sea level, parallel to the shore and separated from it by a lagoon.
What is cavitation?
Collapse of bubbles in waves crashing into and then receding from cliffs and other solid rock features causing energetic pressure waves which break up the rock and enlarge joints and fissures in the rock.
What is a coastline of emergence?
A coastline that has experienced a fall in sea level or tectonic uplift of the land surface.
What is a coastline of submergence?
A coastline that has experienced a rise in sea level or tectonic sinking of the land surface.
What is a constructive wave?
Waves having a long wave length, low wave height and low frequency. The swash tends to be more powerful than the backwash and hence they are associated with the build-up of beach material.
What are Dalmatian coasts?
A submergent landscape of ridges and valleys that runs parallel to the coast and features islands and sea inlets.
What is a destructive wave?
Waves having a short wave length, high wave height and high frequency. The backwash tends to be more powerful than the swash and hence they are associated with the removal of beach material.
What is eustatic sea level change?
A fall or rise in sea level, resulting from changes in the volume of water in the oceans.
What is a fjord?
A glacial trough flooded due to a rise in sea level.
What is a high energy coast?
A coastline with high energy waves where erosion processes typically dominate over deposition processes.
What is isostatic sea level change?
A fall or rise in sea level resulting from the land rising or falling relative to the sea.
What is littoral drift (or longshore drift)?
The process whereby waves approach the shore at an angle and the difference in the direction of swash and backwash transports material along the coast.
What is a low energy coast?
A coastline with relatively low energy waves where deposition rates typically dominate over erosion rates.
What is a mudflat?
A coastal expanse of mud deposits exposed at low tide but inundated by high tides.
What is an offshore bar?
A ridge of sediment parallel to the coast formed of material eroded by destructive waves and transported offshore.
What is a raised beach?
A former beach occupying a higher level than current sea level and deposited when sea levels were higher than at present for a sustained period of time.
What are rias?
A non-glaciated river valley submerged following a rise in sea level.
What is a saltmarsh?
An ecosystem formed on tidal mudflats largely compromising of salt-tolerant plants.
What is a sediment budget?
The balance between the input and output of sediment on a stretch of coast, commonly termed a sediment cell.
What is a sediment cell?
A stretch of coast in which sediments are transferred by various processes between different stores, tending to form a self-contained coastal system.
What is tectonic sea level change?
A fall or rise in sea level, resulting from changes in land surface levels and configuration associated with tectonic processes.
What are tides?
The cyclical rise and fall of the level of the sea in response to the gravitational attractions of the moon and sun.
What is a tombolo?
A ridge of beach sediment that has extended to join a former island to the mainland.
What is wave quarrying?
This involves high energy waves hitting rock faces with sufficient force to enlarge joints and remove particles of rock through vibration.
What is weathering?
Sub-aerial processes occurring above the waterline leading to the disintegration and decomposition of rock.
