Rivers

Question 1

Hydraulic Action

Answer 1

When the water has so much energy that it forces air and water into the cracks, widening them.

Question 2

Abrasion

Answer 2

When pebbles and small rocks hit against a surface (i.e. river bed / sea bed / cliff), wearing away at the rock.

Question 3

Attrition

Answer 3

When the pebbles and small rocks hit against each other in the river / sea, making them smaller, smoother and more rounded.

Question 4

Solution (Erosion)

Answer 4

When the water / sea water dissolves certain types of rocks. (i.e. limestone)

Question 5

Traction

Answer 5

When large rocks or pebbles roll along the bottom of the river / sea as they are too heavy to be carried by the water.

Question 6

Saltation

Answer 6

When small rocks and pebbles are bounced along the river bed and travel with the river / sea.

Question 7

Suspension

Answer 7

When fine material (i.e. silt / sand) is light enough to be carried in the water, travelling with the river / sea and giving it a murky colour.

Question 8

Solution (Transportation)

Answer 8

When minerals are dissolved in the water.

Question 9

Types of weathering + examples

Answer 9

Biological Weathering (Plant roots making cracks in stone), Chemical Weathering (Weak acid rain corroding limestone) and Physical/ Mechanical Weathering (Water flows through cracks, freezes and expands the cracks)

Question 10

Vertical Erosion

Answer 10

Downward erosion of the river bed that usually happens in the upper course.

Question 11

Lateral Erosion

Answer 11

Sideways erosion of the river banks that usually happens in the middle to lower course.