Hazards - Tropical storms

Question 1

How many storms are there per year?

Answer 1

45

Question 2

What is the distribution of tropic stroms? (4)

Answer 2

Eastern Asia - 33%

East Pacific - 17%

West Austrailia - 13%

Caribbean - 11%

Question 3

What conditions are needed for a tropical storm to form? (4)

Answer 3

1 - Disturbance of the sea surface e.g low pressure

2 - Water that’s 27⁰c for at least 50m -

3 - Convergence of air either within the ITCZ or along the boundary between warm and cold air masses. This causes warm air to rise

4 - A location at least 5⁰ from the equator

Question 4

Wh don’t tropical storms form 0-5⁰ either side of the equator?

Answer 4

Because the coriolis effect isn’t strong enough to make the strom spin

Question 5

Why do tropical stoms develop over warm water?

Answer 5

As the evaporation of warm moist water into water vapour releases energy that increases wind speed

Question 6

Why do tropical stoms form in the tropics?

Answer 6

Because the water here is warm enough

Question 7

In what locations do tropical storms occur? (4)

Answer 7

1 - Caribbean sea

2 - Bay of Bengal

3 - China sea

4 - Northern Austrailia

Question 8

What happens when tropical storms move over land and why?

Answer 8

They lose strength because their supply of warm moist air is cut off

Question 9

What is the coriolis effect?

Answer 9

It is a force caused y the Earth’s rotation. It deflects the path of winds but it’s weak at the Equator

Question 10

What is the general pattern of movement of tropical storms? (2)

Answer 10

1 - Initially move westwards due to easterly winds in the tropics

2 - They move away from the equator because of the coriolis effect

Question 11

What are the key features of a tropical storm? (3)

Answer 11

1 - Circular in shape

2 - 100’s km wide

3 - Last 7-14 days

Question 12

What direction do tropical storms spin in the Northern hemisphere?

Answer 12

Anticlockwise

Question 13

What direction do tropical storms spin in the southern hemisphere?

Answer 13

Clockwise

Question 14

What is the centre of the storm called and what is a key fetaure of this?

Answer 14

An area of very low pressure called the eye

Question 15

What causes strong winds in the tropical storm?

Answer 15

Rising air spiraling around the eye in the eyewall

Question 16

What extends for a long distance either side of the eye and why? (2)

Answer 16

1 - Cloud cover

2 - Because near the top of the storm there is an outflow of moist air

Question 17

How are storms classified?

Answer 17

Using the Saddir-Simpson scale

Question 18

What is the Saffir-Simpson scale based on?

Answer 18

Wind speed

Question 19

What is the scale for the Saffir-Simpson scale?

Answer 19

Category 5 -1

(strongest-Weakest)

Question 20

What can the Saffir-Simpson scale estimate?

Answer 20

How much damage a strom will cause

Question 21

Are tropical stroms frequent and why isn’t this a major issue? (2)

Answer 21

1 - Yes, roughly 100 per year

2 - However some never reach land so don’t develop into a major hazard

Question 22

Where and When are tropical stroms most frequent? (2)

Answer 22

1 - Northern hemisphere: June - Nov

2 - Southern hemisphere: Nov - Apr

Question 23

How can the path of tropical storm be predicted?

Answer 23

1 - Certain cloud formations in tropical areas can be identified from satellite imagery - used to tell when a tropical storm is forming

2 - The storm can be trcaked using satellite imagery and models - used to tell when and where it is likely to hit land

Question 24

What is the effect of high wind speeds in tropical storms? (3)

Answer 24

1 - Destroy buildings

2 - Uproot trees

3 - Carry debris long distances before smashing them into other objects

Question 25

What wind speeds on the ground can tropical stomrs reach?

Answer 25

More than 300km/h

Question 26

What is a storm surge? (2)

Answer 26

A large rise in sea level caused by:

1) High winds pushing water towards the coast
2) The low pressure of a storm

Question 27

What is an example of heavy rainfall caused by a tropical storm?

Answer 27

Denise - 1966:

1000mm rain felll in 12 hrs at La Reunion

Question 28

What are the effects of heavy rainfall from a strom surge? (2)

Answer 28

1 - Flooding

2 - Landlsides - water infiltrates soil and rock making it less stable

Question 29

What are the 5 storms hazards?

Answer 29

1 - High winds

2 - Storm surges

3 - Heavy rain

4 - Flooding

5 - Landslides

Question 30

What are the social impacts of storm surges? (5)

Answer 30

1 - Debris carried in flood water - kill people

2 - Destroyed houses - homelessness

3 - Electricity cables damaged + Cut off supplies

4 - Flooding results in sewage overflows contaminating water - spread disease

5 - Damage to agricultural land - food shortages

Question 31

What are the political impacts of storm surges? (2)

Answer 31

1 - People may blame the authorities for food shortages / lack clean water - leading to conflict and political unrest

2 - Repairing damages - stunt development

Question 32

What are the economic impacts of strom surges? (3)

Answer 32

1 - Repairing infrastructure costly

2 - Damaged business can’t trade

3 - Agricultutal land damged - less farming

Question 33

What are the environmental impacts of storm surges? (4)

Answer 33

1 - Beached eroded

2 - Coastal habitats damaged

3 - Sediment depositied in aquatic ecosystems may damage fish breeding grounds

4 - Environments polluted by chemicals and oil spilled from damaged factories

Question 34

What are long term responses to a storm surge? (5)

Answer 34

1 - Don’t build new developments in high risk areas

2 - Governments can plan evacuation routes

3 - Educate people on how to prepare for a storm

4 - Offer disaster training to emergency services

5 - Buidling flood defences along rivers and coasts

Question 35

How can infastructure be developed to withstand a tropical storm? (3)

Answer 35

1 - Using reinforced concrete

2 - Securly fixing roofs

3 - Building infrastructure on stilts

Question 36

What are the short term responses to a storm surge?

Answer 36

Evacuating people from high risk areas