Geography unit 1 section A - The challenges of natural hazards

Natural hazard definition

Environmental events threatening people

What are the most deadly natural hazards

• floods

• Tropical storm

• Earthquakes

• Droughts

What factors affect the risk of natural disasters

• urbanisation

• Poverty

• Farming

• Climate change

The mechanisms that drive plate movement

The earths major tectonic plates

Earthquake definition

A sudden violent period of ground-shaking.

Constructive plate margin

When two plates move apart

Destructive plate margin

Where two plates move towards each other

Conservative plate margins

Where two plates move past each other at different rates

Primary effects of earthquakes

• (caused by the ground shaking)

• Destroy building and infrastructure

• Kill and injure

Secondary effects of earthquakes

• (resulting from shaking)

• Includes fires, landslides, tsunami

Nepal, April 2015 earthquake effects

Japan, March 2011 earthquake effects

Responses to the Japan and Nepal earthquakes

Why do people live at risk from tectonic hazards

• Volcanoes bring benefits like fertile soil, hot water, and rich mineral deposits

• Earthquakes and volcanic eruptions are rare, so not seen as a great risk

• Poor people have no choice- money, food, and family are seen as more important

How can risk from tectonic hazards be reduced

• monitoring

• Prediction

• Protection

• Planning

Global atmospheric circulation

What are Tropical storms

Huge storms referred to as hurricanes, cyclones and typhoons.

Where do tropical storms form

Most form 5-15 degrees north and south of the equator

What causes tropical storms to form

• ocean temperatures above 27 degrees Celsius

• The spinning (Cloriolis) effect of the earths rotation is very high

• Intense heat and humidity makes air unstable causing it to rise rapidly

Structure and features of tropical storms