Hazards

HideShow resource information

Describe a divergent boundary

Divergent is when the 2 plates move away from each other and form new crust
It is formed by low level eruptions

1 of 20

Describe a transform boundary

The plates move in direction against one another. They move in different speeds and it causes a build in tension.

2 of 20

Describe a convergent boundary

This is where the plates come together and the oceanic gets stuck beneath the continental in which builds up tension and causes and earthquakes. Or the crust is destroyed forming new crust

3 of 20

What is a natural hazard

A dangerous phenomenon that my cause loss of life , injury or other health impacts, property damage, loss of life and services, social and economic disruption or environmental damages.

4 of 20

Describe the natural hazard risk equation

The equation can be used to determine the level of risk a population will face. This can create a statistical impact of the size of the impact of an event.

V and c can alter between countries . In MEDCS they are less vulnerable to hazards and have a higher carrying capacity due to the amount of money they have and also their improved infrastructure. Where as in lEDCs they are more vulnerable and have a lower carrying capacity, they have less money to deal with the hazard and the infrastructure does to have building regulations

5 of 20

Hazard management strategy

Post disaster

Response - the effectiveness depends on education , training and experience or emergency recovery reposes

Recovery - action to assist communities to return to predisaster conditions

Redevelopment- action to manage economic loses, there should be a long term link between national economic activities

Pre coaster

Prevention- action to reduce severity of impact

Mitigation- action to minimise property and economic damage

Preparedness- action to increase speed and efficiency response

6 of 20

Draw the disaster impact cycle

7 of 20

Explain prediction of earthquakes

Prediction is highly unreliable. For example we can measure the movement of the ground but small quakes are not always an indication that a big one is around the corner

We can also try to measure stress levels but still this is not always effective ( San Andreas fault reference)

We also can look for a historical pattern

8 of 20

How can we prepare for an earthquake

In California in the USA it is prone to serious earthquakes. To become prepared they have introduced the following to reduce the loss of life

Practice drills

Evacuation plans

Disaster planning- planning refugee camps , medication, water purification and search and rescue

All of these factors are influenced by money

9 of 20

How can you prevent damage

Damage can be prevented by the construction of buildings. Firstly the buildings must have enforceable regulations. However these are largely ignored in LEDCS due to bribes and corruption

Secondly the design is important. They must be solid steel structures with wide bases and deep foundations. Some also may have counter weights which allow the building to sway

10 of 20

How can earthquakes be predicted

Monitoring and prediction is very good - mount st Helens

We can monitor ground temperature ( as the magma rise the temperature rises), soulful dioxide and hydrogen chloride. As we look at the deformation and seismic waves.

11 of 20

How can we prevent damages

Hazard zoning areas

12 of 20

Define mass movement

Mass movement is the downhill transfer of slope material. It includes any large scale movement of the earths surface that it accompanied by a movie agent such as a river glacier or ocean

13 of 20

Describe flows

Fastest flowing

They are characterised by internal movements of individual grains within the flow itself. Hey internal flow can be fast and chaotic if it originates from a steep slope or contains a lot of water. Or grain movements can be very slow and somewhat predictable if the slope surface is very gradual in its angle

14 of 20

Describe falls

These are fast moving rock falls in which pieces of rock travel down a slope. The size of the rock that falls can vary. An example of a rock fall is Pennington point in South East Devon in which receives continuous coastal exposures from the river otter.

15 of 20

Describe a translation slide

A down slope movement of material that occurs along a distinctive surface of weakness such as a fault or join bedding plain. If the slip is straight then it is termed transnational

16 of 20

Describe rotational slip

Characterised by the movement along up failure surface. The upper unit of the slump is typically tilted back and surface water may be retained in the depressed zone. It is normally found in uniform relatively weak material e.g. Clay.

17 of 20

Describe a creep

A creep takes many years and can form terraces in the ground. It occurs when sediment expands and individual particles are lifter up at right angles to the slope. Sediments can expand when they freeze , are heated up or get wet. When the sediments shrink the particles fall straight back down

18 of 20

Define the following

Shear strength- internal resistance of a body to movement

Shear stress- the force acting on a body that causes it to move down a slope

Anything that reduces the strength and increases the stress causes slope failure

19 of 20

What increases mass movement

Construction of infrastructure

Heavy precipitous puts weight on the land

Snow melt due to global warming

Roads and traffic put weight on land

20 of 20

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Hazards resources »