SC Geog Worksheet 9.3 Mass Movement Close Test

Two processes of mass movement that I have studied are ​ (a)   and ​ (b)   .

• soil creep
• mudflows
• regolith
• saturation
• Sahel
• mass movement

Soil creep is the ​ (a)   form of mass movement that occurs on ​ (b)   slopes of between 10° and 15° at a

maximum speed of ​ (c)   cm per year. Soil creep is most common in ​ (d)   areas, such as the ​ (e)   of Ireland, where temperatures regularly go above and below 0 °C.

• slowest
• gentle
• 0.5
• upland
• west
• fastest
• extreme
• 0.10
• east
• lowland

When temperatures fall below 0 °C, the water in the soil freezes and expands, causing the soil particles to be forced ​ (a)   and ​ (b)   from each other. When the soil ​ (c)   again, the loosened soil ​ (d)   , allowing the soil to fall downhill due to ​ (e)   .

• upwards
• away
• thaws
• contracts
• gravity
• downwards
• towards
• loosens
• expands
• force

Soil creep also occurs due to ​ (a)   and ​ (b)   cycles as the soil absorbs water during times of ​ (c)   rainfall.

• wetting
• drying
• heavy
• turning
• drought
• light
• low
• flushing

As the soil particles expand, they are forced upwards and away from each other before shrinking and ​ (a)   back downwards when they ​ (b)   . As the particles ​ (c)   , space is created between them, allowing them to creep ​ (d)   due to gravity.

• sinking
• dry
• shrink
• downslope
• settling
• clean
• expand
• back
• upland
• across

Wetting and drying cycles are effective in soil that lies on slopes of ​ (a)   rock, as ​ (b)   occurs more frequently.

• impermeable
• saturation
• permeable
• percolate
• drying
• wetting
• hard
• soft
• solifluction

​ (a)   occur due to the severe saturation of ​ (b)   on a slope, usually after heavy rainfall. Mudflows typically occur on steep slopes that have underlying impermeable rock. Once the soil becomes over ​ (c)   per cent water, it has the ability to flow as ​ (d)   between it and the underlying rock is reduced. With the friction reduced, the soil begins to flow down the slope, at speeds of up to ​ (e)   km/h.

• Mudflows
• regolith
• 30
• friction
• 100
• 50
• 10
• Earthflows
• soil
• danger

The soil flows into ​ (a)   and ponds as it moves downslope, increasing its ​ (b)   content and allowing it to move faster. If the water content is far above 30 per cent, the soil will have a lower ​ (c)   , which allows it to move faster and over a ​ (d)   area.

• streams
• water
• viscosity
• wider
• lakes
• lubrication
• density
• thinner
• valleys
• liquid

If the mudflow has a ​ (a)   water content it will have a higher viscosity, which reduces its speed and the distance it travels. When mudflows reach ​ (b)   , open land, they spread out and quickly lose their ​ (c)   .

• lower
• flat
• speed
• higher
• clear
• upland
• lowland
• saturation
• cool
• density