Hazards 4 marker Exam Qs

Question 1

Outline the processes involved in the formation of ocean ridges

Answer 1

• divergent plate margins with plates moving apart
• convection currents pull plates apart
• slab push also pulls the plates apart
• force when mantle pushed upwards causing eruptions on the sea floor

Question 2

outline the different physical categories of natural hazards

Answer 2

• geophysical hazards such as earthquakes and volcanos
• hydrological hazards such as flash floods, hazards caused by water from other hazards
• atmospheric hazards that occur due to processes in the atmosphere such as tropical storms and hurricanes

Question 3

Explain the concept of slab pull in relation to plate movement

Answer 3

• slab pull associated with destructive/ convergent plate margins where subduction zones occur
• the subduction plate is denser and is forced to sink under the less dense plate
• with gravity acting on the edge (leading) of the plate, this helps to pull the rest of the plate with it

Question 5

Outline the process of liquefaction

Answer 5

• vibrations in the earth are caused by earthquakes
• this breaks the bonding between particles in the earths surface causing solid ground to turn to liquid
• ground unable to hold weight meaning anything on top of it collapses
• mainly occurs in waterlogged areas
• on a slope this results in the downward movement of soil

Question 6

Explain what is meant by the term coastal storm surge

Answer 6

• a coastal storm surge is a temporary rise in sea level due to tropical storms
• the storms produce strong winds which combined with the low pressure environment causes uplift, pushing the water onto the shore
• this can often overcome flood barriers/ levees

Question 7

Comment on the different causes of wildfire events, both human and natural agency

Answer 7

• human causes of wildfire can be due to arsenic or can be unintentional such as electrical fires
• natural causes can be due to high temperatures with dry windy conditions (spontaneous heating)
• natural causes can also be lightning
• most common human cause of wildfire is cigarettes
• a wildfire is a uncontrolled unplanned land fire

Question 8

Explain the concept of slab pull in relation to plate movement

Answer 8

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