HAZARDS: Storm Hazards

Question 1

Tropical storms

Answer 1

Large spinning storms with strong winds + torrential rain.

Question 2

What conditions are needed for a tropical storm?

Answer 2

• Disturbance near the sea-surfcae, eg. low pressure
• Warm water (above 27^oC to at least 50m below surface) = lots of evaporation
• Convergence of air in lower atmosphere - forces warm air to rise
• At least 5^o from the Equator, as this is where coriolis effect is strong enough

Question 3

What are tropical storms in the Caribbean Sea called?

Answer 3

Hurricanes

Question 4

What are tropical storms in the Bay of Bengal called?

Answer 4

Cyclones

Question 5

What are tropical storms in the China sea called?

Answer 5

Typhoons

Question 6

Why do tropical storms lose strength over land?

Answer 6

Supply of warm, moist air is cut off.

Question 7

What do tropical storms initially do?

Answer 7

Move westwards due to easterly winds in tropics

Question 8

Why do tropical storms move away from the equator?

Answer 8

Due to Coriolis effect.

Question 9

How long do tropical storms usually last?

Answer 9

7-14 days

Question 10

How do tropical storms spin in the northern hemisphere?

Answer 10

Anticlockwise

Question 11

How do tropical storms spin in the southern hemisphere?

Answer 11

Clockwise

Question 12

Describe the structure of a tropical storm:

Answer 12

• Area of low pressure at centre = eye
• Rising air spirals around eye in the eyewall, causing strong winds
• Outflow of moisture-laden air near top = cloud cover extends for a long distance

Question 13

How are storms classified?

Answer 13

Using the Saffir-Simpson Scale, which is based on wind speed.

Question 14

How does the Saffir-Simpson Scale work?

Answer 14

• Rates storm hazards on a scale from 1-5 (category 5 is the strongest)
• Estimates how much damage a storm of a given magnitude will do

Question 15

Category 5

Answer 15

Stongest storm hazard.

Winds over 250km/h

Question 16

Category 1

Answer 16

Weakest storm hazard.

Winds of 120-150km/h

Question 17

Describe the frequency of tropical storms:

Answer 17

Around 100 a year.

Northern hemisphere - June to November

Southern hemisphere - November to April

Question 18

Why can the path of a tropical storm be predicted fairly accurately?

Answer 18

Cloud formations can be identified by satellite imagery - shows formation of tropical storm.

Can then be tracked using satellites and models.

Question 19

What are some of the forms a storm hazard can take?

Answer 19

High winds

Storm surges

Heavy rain

Flooding

Landslides

Question 20

Storm surge

Answer 20

A large rise in sea level caused by high winds pushing water towards the coast, and by the low pressure of a storm.

Question 21

How can the impact of storm hazards be reduced by prevention?

Answer 21

Cannot be prevented, but can be studied to identify high-risk areas.

Future developments can be planned to avoid these.

Question 22

How can the impact of storm hazards be reduced by prepardness

Answer 22

• Emergency services cna train + prepare for disasters
• Evacuation routes can be planned
• Education

Question 23

How can the impact of storm hazards be reduced by adaptation?

Answer 23

• Buildings can be designed to withstand storms + floods
• Flood defences can be built