TOPIC 1 - coasts glossary Flashcards
(25 cards)
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 the receding from cliffs in which causes energetic pressure waves in which break up 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?
has a long wavelength,low height and frequency
swash is stronger than backwash more deposition occurs
what is a destructive wave?
short wave length,high height and high frequency
backwash stronger than swash removes material
what is a dalmatian coast?
submergent landscape of ridges and valleys that run parallel to the coast.
what is eustatic sea level change?
a rise or fall in sea level resulting in changes in volume - usually connected with global changes.
what is a fjord?
a glacial trough flooded due to rise in sea level.
what is a high energy coast?
a coastline with high energy waves where erosion dominates over deposition.
what is a 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 ( LSD ) ?
waves approaching the shore at an angle and the difference in swash and backwash transports material along.
what is a low energy coast?
low energy waves where deposition rates dominate over erosion rates.
what is a mudflat?
a coastal expanse of mud deposits exposed at low tides but inundated at high tides.
what is an offshore bar?
a ridge of sediment parallel to the coast formed of eroded material and transported offshore.
what is a raised beach?
a former beach occupying a higher level that current sea level and deposited when sea levels were higher that at present for a sustained period of time.
what is a rias?
a non glaciated river valley submerged following a sea level rise.
what is a salt marsh?
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 (sediment cells)
what is a sediment cell?
a stretch of coast in which sediments are transferred by various processes between the stores in which forms a self contained coastal system.
what is tectonic sea level change?
a fall or rise in sea level due to changes in land surface levels and configuration.
what is a tide?
the cyclical rise and fall of the level of the sea in response to the gravitational attraction’s of sun and moon.
what is tombolo?
a ridge of beach sediment that has extended to join a former island to the mainland.
what is wave quarrying?
high energy waves hitting rock faces with force to enlarge joints and remove particles through vibrations.
