Describing distribution

• Can you see patterns or do they occur randomly?

• Do they occur on land or in the sea? • Which continents can you identify? • Are they north or south of the equator? • What is the latitude? – degrees north and

south of the equator e.g. the tropic of cancer is 23o north

Distribution of tropical storms

Lesson objectives:To describe the characteristics and causes of tropical storms

Use your skills to analyse this photograph

Characteristics? – what do we already know?

• What are typhoons like?

Location

• Tropical storms are normally found between the tropics near the Equator.

• The formation of tropical storms is not fully known, but scientists do know that they draw their energy from warm seas.

High winds

• High Winds : In severe tropical storms the maximum sustained winds can approach 200 km/h with short period gusts closer to 300 km/h.

• Such violent winds can devastate natural vegetation and all but the strongest man-made structures.

Flooding

• Heavy rainfall is associated with tropical storms. Heavy rainfall actually causes much more damage and deaths than high winds.

Landslides

• Landslides are a secondary hazard. Landslides can be triggered when large amounts of rainfall saturate the ground increasing the stress on the slope.

Storm surges

• Tropical storms moving in land can create storm surges and big waves. If tropical storms coincide with spring tides the impacts can be severe

Measuring tropical storms

Storms below 74mph (119kph) are described as only tropical storms. Anything above this speed is officially a hurricane/cyclone/typhoon.

Saffir Simpson Scale

Weather – some basics • Air Pressure

Simply the weight of air pressing down onto the surface of the earth. • When air is warm it normally rises and creates an area of low pressure. When it

is cool it sinks and creates an area of high pressure.

• Pressure is measured on a barometer. It is normally measured in millibars (mb).

Wind

• Wind is created by air moving from areas of high pressure to areas of low pressure.

• This can happen on a local scale or on a global scale

Formation of tropical storms • http://ih-igcse-geography.wikispaces.com/3.2+Characteristics%2C+distribu

tion+and+causes+of+tropical+storms

Questions

• Why do hurricanes / typhoons / cyclones form close to the equator?

• Why are there strong winds during a typhoon? • Why is there heavy rain during a typhoon?