revision for EQ2 point 4.3/4.4 Flashcards
Ballards point
Long shore drift, has a curve, not an open area/its tight area.
Coastal erosion
Costal erosion is the gradual wearing away of material (coast line) by the the action of waves. This material is then moved or deposited elsewhere.
Softer rock
Headlands and bays. … Headlands are formed when the sea attacks a section of coast with alternating bands of hard and soft rock. The bands of soft rock, such as sand and clay, erode more quickly than those of more resistant rock, such as chalk. This leaves a section of land jutting out into the sea called a headland.
Harder rock
Hard rocks are more resistant than soft ones, and will form steep cliff faces. This nearly vertical cliff on the north Cornish coast has been formed from basalt, a very hard igneous rock. Despite being exposed to the full force of the sea and frequent gales, it remains almost vertical.
Direct
Occurring because of something being purposely put in place to protect the area of the coastline
Indirect
Occurring because of something used to protect the another area of the coastline
Weathering
It takes place on the land. Most weathering involves the breakdown of rocks but not their removal.
Rock structure
It means the way rocks are arranged, most rocks are in layers of strata.
Rock strata
It can be arranged in 2 ways along the coastline: concordant = parallel to the coastline.
Discordant = perpendicular (90 degrees) to the coast.
Freeze thaw weathering
The water enters the cracks and at night the temperature drops and the water freezes and it expands by 9 percent increase in volume and the pressure is increasing because the ice is pushing against the rocks and it increases their cracks. During the day the temperature increases and the ice in the rocks melt. In the night time the temperature drops, re freezing of more water thats got into the bigger crack. After many cycles this happens again.
Biological weathering
Plant roots and animals burrow into rock and pressure on the rock and break down the structure if the rock and after continuous cycles large cracks are formed
Chemical weathering
Is when chemicals break down rock as a result of a chemical reaction
Hydraulic action
Hydraulic action: is the power and force of water and waves being forced into cracks in the rock
The pressure increases and expands. Rock chips off and the crack gets bigger.
Abrasion
Abrasion: is when rocks are picked up by air and thrown or rubbed against the cliffs.
This action wears away the rock and it is gradually removed.
Solution
Solution: is when the sea becomes very slightly water acidic. This is caused by vegetation near to the cliffs.
This dissolves rocks such as limestone/chalk