Lithosphere (coasts) Flashcards
what is hydraulic action
when the sheer force of water forcing air into cracks causing them to be dislodged
what is abrasion
when the rocks, sand, and shingle are thrown against cliffs and scrape rocks off
what is solution
when salts and other acids in the water dissolve minerals in the rocks
what is attrition
waves causing rocks to hit off each other and break into smaller particles
Headlands and bays are formed due to what
differential erosion
what happens to softer and harder rock
softer rock is less resistant so erodes away faster that hard more resistant rock
is a headland an area of hard or soft rock that juts out into the sea
hard rock
what is a bay
a sheltered area of rock between headlands
what happens to weaknesses( joints, faults,cracks) in cliffs
they are undercut to form a wave cut platform
what happens to headlands with weaknesses (joints, faults,cracks)
eroded by the sea to form caves
how is an arch formed
when erosion on both sides of the headland cuts through the back wall and enlarges cave
how does a blowhole form
when compressed air is pushed through the roof of the cave by powerful waves ( vertical erosion)
how is a sandpit formed
by longshore drift
what is swash
when waves driven by prevailing winds push material up the beach at an angle
what is backwash
backwash is dragged back by gravity down the beach at right angles
when are spits formed
when there is a change in direction on a coastline
what may form in a sheltered area behind a spit
salt marsh
explain the formation of a tombolo
formed when a spit extends out from mainland connecting to an island
how is a sandbar formed
due to longshore drift
when are sandbars formed
when a spit grows across the enterance to a bay, connecting 2 headlands
when are bars formed
when the is a change in direction along a coastline, allowing a sheltered area for deposition
