Natural Hazzard

Question 1

What is a natural hazard?

Answer 1

A natural event that threatens people or has potential to cause damage, destruction and death

Question 2

What are the different types of hazzard?

Answer 2

•Atmospheric
•Geological
•Water Based
•Biological

Question 3

What is an atmospheric hazzard?

Answer 3

Created in the atmosphere by the weather/by the movement of air an water e.g. wind,tornadoes,snow

Question 4

What is a geological hazzard?

Answer 4

Created by the movement of the Earth’s tectonic plates or surface rock and soils e.g. earthquakes, landslides

Question 5

What is a water based hazard?

Answer 5

Created by rivers,sea or oceans e g. floods

Question 6

What are biological hazzards?

Answer 6

Any biological substance that poses a threat to the health of people e.g. wildfires

Question 7

What are some human factors affecting hazard risk?

Answer 7

•Planning Laws-Teaching the population how to prepare and respond to an earthquake can reduce the hazard risk.
•Frequency-The more often a population is affected by a hazard, the more likely they are to adapt their way of life to cope
•Strength of infrastructure- infrastructure in HICs may be built with cross bracing to avoid collapsing

Question 8

What are some physical factors that are affecting hazard risk?

Answer 8

*Magnitude-This is the size of the hazard event. The greater the force of the hazard the more likely it is the hazard will have a greater impact on people
*The Rock Type-An earthquake in an area of soft rock is larger and lasts longer than one in an area of hard rock. Soft rock also makes the risk of liquefaction greater whixh can damage buildings
Coastline Shape-For example, a gently sloping coastline will often suffer more damage than a steep coastline in a hurricane’s storm surge

Question 9

What is the crust?

Answer 9

The outermost layer of the Earth

Question 10

What is the mantle?

Answer 10

A layer of rock between the core and the crust made of soft molten rock (3800°C)

Question 11

What is the outer core?

Answer 11

It is dense hot rock at the centre of the earth made of liquid iron and nickel (5500°C)

Question 12

What is the inner core?

Answer 12

It is dense hot rock at the centre of the earth (5500°C)

Question 13

Why do tectonic plates move?

Answer 13

Convection currents in the mantle

Question 14

What are convection currents?

Answer 14

the motion of molten rock in the mantle as heat rises in the earth’s core heating up magma and causing it to rise

Question 15

What are the different types of crust?

Answer 15

Oceanic and continental

Question 16

What are the features of oceanic crust?

Answer 16

•found under sea
•is thin(5-10km)
•very dense

Question 17

What are the features of continental crust?

Answer 17

•found under land
•is thicker than oceanic crust (20-200km)
•less dense

Question 18

What are earthquakes?

Answer 18

Vibrations in the earth’s crust that create a sudden shaking in the surface

Question 19

What are volcanoes?

Answer 19

A landforms created by magma being forced into the earth’s crust and erupting onto the earth’s surface through a vent

Question 20

What are 2 different types of volcanoes?

Answer 20

Composite and Sheild

Question 21

What is a composite volcano?

Answer 21

•found at destructive plate margins
• steep sided, layers of ash and lava, magma is very sticky and cools quickly
•very explosive

Question 22

What is a shield volcano?

Answer 22

•found at constructive plate margins
•dome shaped with sloping sides
•magma is runny and flows long distances before it cools
•more gentle explosions

Question 23

What happens at a destructive plate margin?

Answer 23

•Where an oceanic plate meets a
continental plate. They are moving
towards each other.
•The denser oceanic plate is subducted beneath the less dense continental plate.
•As it sinks, it melts and makes magma called andesite.
•The sinking oceanic plate can stick to the continental plate, pressure builds up against friction causing earthquakes
•volcanoes are formed when the pressure of the magma builds up beneath the Earth’s surface. The magma escapes through weaknesses in the rock and rises up through a composite volcano

Question 24

What happens at a constructive plate margin?

Answer 24

• Where two oceanic plates are moving apart from each other.
•New oceanic crust is forming constantly in the gap created.
•The magma is injected between the two plates. As it cools it forms new oceanic crust.
•The magma is runny. Shallow sided
volcanoes form
•Earthquakes are caused by friction as the plates tear apart.

Question 25

What happens at a conservative plate margin?

Answer 25

• As plates slide past each other,
friction between them causes
earthquakes.
•Plates can be moving in different
directions or the same direction.
•No volcanoes are formed.