geography weathering,mass movement

Question 1

Name 3 types of weathering

Answer 1

Mechanical weathering Chemical weathering Biological weathering

Question 2

what is mechanical weathering?

Answer 2

Mechanical weathering involves rocks being physically broken apart.Mechanical weathering produces broken rock called scree (or regolith).Scree can be found on mountain slopes.

Question 3

What is chemical weathering?

Answer 3

Chemical weathering involves rock being dissolved gradually over time.

Question 4

How does freeze thaw action occur?

Answer 4

Freeze-thaw weathering occurs when rocks are permeable (allow water to pass through). Water enters cracks(joints) in the rock. When temperatures drop, the water freezes and expands causing the crack to widen(about 10%).Overtime ,the rock breaks and collapses into smaller pieces of rock called scree.Scree can be found on the sides of many mountains .

Question 5

What is carbonation?

Answer 5

It’s a chemical weathering process.It’s the process of rock being dissolved by a weak carbonic acid.Limestone is particularly affected by acid rain because of its characteristics.

Question 6

What are the characteristics of limestone?

Answer 6

1.It’s a soft sedimentary rock.The shells of dead sea creatures (fossils)fell to the ocean floor.They mixed with sediments and build up stratas.
2.each strata was separated by horizontal cracks called bedding planes.Each layers also had vertical cracks called joints.
3.Bedding planes and joints make limestome permeable-water can pass through it.
4.Limestone is composed of calcium carbonate,because of the fossils it contains.Acid rain reacts with calcium carbonate and dissolves it.

Question 7

how does karst landscapes form?

Answer 7

When acid rains falls on limestone,it dissolves the weaker parts of the limestone surface.These weaken parts deepens and form grikes overtime.The slabs between the grikes are called clints. The pattern of clints and grikes make up limestone pavements.Areas of bare limestones pavements are called karst landscape.

Question 8

What does denudation mean?

Answer 8

It’s weathering and erosion.

Question 9

What does weathering mean?

Answer 9

It’s the break down of rocks by weather wher the rock lies.

Question 10

What does erosion mean?

Answer 10

It’s the wearing away and transportation of rocks by rivers ,glaciers,the sea, and wind.

Question 11

How does passages and caves form?

Answer 11

Water can seep down through limestone because it is a well joined permeable rock.The slightly acidic water weathers the limestone as it passes through it.

Question 12

How does stalactites , stalactites and pillars form?

Answer 12

Water containing calcite evaporates off the ceiling of caves and over time stalactites form.Below the stalactites ,drips of calcites form stalagmites over tome.If stalagmites and stalactites join together ,pillars form.

Question 13

Give an example of a unique landscape.

Answer 13

The Burren in north Co.Clare.

Question 14

Describe the factors affecting mass movements.

Answer 14

Water,vegetation,gradient and human activity.If all four factors are combined,very severe mass movements can occur.

Question 15

Explain how water affects mass movement.

Answer 15

Water separates soil particles and makes them flow more easily.

Question 16

Explain how vegetation affects mass movements.

Answer 16

The roots of vegetation bind the soil together.If the vegetation is removed,the soil will move more easily.

Question 17

Explain how gradient affects mass movement.

Answer 17

Gradient is slope.The steeper the slpoe ,the more likely mass movement will happen.

Question 18

Explain how human activity affects mass movements.

Answer 18

Human activity can also contribute to mass movement by,for example. undermining the base of slopes.

Question 19

Describe how to prevent mass movements.

Answer 19

We can try to limit mass movement by taking action to stabilise slopes.
1.Planting vegetation reduces movement because roots bind the soil together.
2.Improving drainage ensures too much water does not build up in the soil.
3.Building retaining walls can help hold back a slope.