coasts

Question 1

what is corrosion

Answer 1

when chemicals in the seawater dissolve rocks,causing them to breakup

Question 2

what is corrasion

Answer 2

when rocks and pebbles carried by waves crash against the cliffs wearing the rocks away

Question 3

what is hydraulic action

Answer 3

when the sheer force of waves crashing against the shore and cliffs. the power of the waves forces air into cracks, compresses it and blows the rock apart

Question 4

explain the formation of headlands and bays

Answer 4

-found in areas where the are bands of alternating hard rock and soft rock

-the headlands and bays are formed by differential erosion

-the softer rock erodes backwards more quickly forming bays

-when formed the bays then become sheltered by the headlands and erosion slows down

-the hard rock erodes more slowly forming headlands which are left sticking out as rocky outcrops

Question 5

explain the formation of headland erosion

Answer 5

-lines of weakness start to form on the headland due to erosion from wave action

-this can happen due to hydraulic action where the force of the waves and air being compressed into cracks can erode the rock

-Continuous erosion will open up the lines of weakness and it will develop into a sea cave

-This can happen due to corrosion where stones and pebbles are repeatedly thrown against the cliff face by wave action, wearing it away

-further erosion of the cave, often an opposite sides of the headland, will form an arch

-this can happen due to corrosion where chemicals such as salts and acids in the sea water dissolve the rock

• the arch is eroded until it eventually collapses forming a free standing piece of rock called a stack

Question 6

formation of a sand spit

Answer 6

-spits are formed when large amounts of sediment are transported by longshore drift

-waves move sand up the beach at an oblique angle due to the prevailing wind. The sand moves back down the beach at a right angle or straight back due to gravity

-over time more material is carried out further and deposited, specially where the sea is relatively shallow and it becomes more sheltered

-once enough material has built up this can be seen above water level. This build up continues gradually as the beach extends itself into open water forming a sand spit

• a salt marsh can form in the protected area behind the spit

Question 7

explain the formation of a sand bar

Answer 7

-spits are formed when large amounts of sediment are transported by longshore drift

-waves move sand up the beach at an oblique angle due to the prevailing wind. The sand moves back down the beach at a right angle or straight back due to gravity

-over time more material is carried out further and deposited, specially where the dead is relatively shallow and it becomes more sheltered

-once enough material has built up this can be seen above water level. This build up continues gradually as the beach extends itself into open water forming a sand spit

-in the time the spit might extend across the bay and join up with the beach on the other side of the sand bar