weather hazards ✓ Flashcards
how does atmospheric circulation cause tropical cyclones ?
- air moves around the world it moves away from the equator
- begins to rotate because of the need to disperse the high levels of heat at the equator across the earths surface
how do tropical cyclones form ?
- most commonly early autumn when sea temperatures are at highest
- air above warm ocean is heated
- when ocean reaches at least 27°C warm air rises quickly causing area of low pressure
- air continues to rise quickly it draws more warm moist air up from above the ocean leading to strong winds
- rapidly rising warm air spirals upwards due to Coriolis force
- warm air rises it cools and condenses forming large cumulonimbus clouds
- these clouds create eye wall and produce heavy rainfall
- centre of cyclone known as the eye is where cold air sinks forming the eye and in here the conditions are dry and calm
what are the characteristics of tropical cyclones ?
- form towards the end of summer and in the autumn
- feature strong winds, heavy rain and often thunderstorms
- average wind speed is 120 kph - 400 kph
- normally move east to west with the trade winds
- have an eye, calm centre of the storm
- have an eye wall which surrounds the eye it is a high density of cloud
where are tropical cyclones found ? why ?
found close to the equator because that is where the sea is the warmest
how do tropical cyclones cause high winds ?
air continues to rise quickly it draws more warm moist air up from above the ocean creating strong winds
how do tropical cyclones cause intense rainfall ?
warm air rises quickly and then cools and condenses forming cumulonimbus clouds which form the eye wall and produce heavy rainfall
how do tropical cyclones cause landslides ?
- saturate soil quickly
- can cause unstable slopes
how do tropical cyclones cause storm surges ?
- produce strong winds that push the water into shore
- can lead to flooding
- makes storm surges very dangerous for coastal regions.
how do tropical cyclones cause coastal flooding ?
combination of high winds, heavy wave action
what are the affects of storm surges ?
- erodes beaches
- erode coastal habitats
- damage coastal defences
- contaminate farmland
- contaminate fresh water
what are the affects of coastal flooding ?
- flooding
- risk of property, people, farming, tourism
- environmental flooding by salt water can be damaging
what are the affects of landslides ?
- risk people
- risk property
- risk local environment
- river flooding can be made if landslide blocks river channel
what is the movement of tropical cyclones ?
- do not remain where they are formed
- they follow the direction of the local prevailing winds
- the track of the tropical cyclone affects how strong it becomes when the cyclone is on dry land it loses its energy from its source the ocean
what were the social impacts of Hurricane Sandy on the USA ?
- 117 people were killed
- nine million homes had power cuts
- 650,000 homes were damaged or destroyed in the whole of the USA
- the streets of New York were flooded as was the subway
what were the economic impacts of Hurricane Sandy on the USA ?
- insurance claims in New Jersey totalled US$3.3
- Us$1.1 billion spent in repairing the damage to sewage and water people I New Jersey and New York
- damage cost in New York totalled US$19 billion
what were the environmental impacts of Hurricane Sandy on the USA ?
- the storm surge meant sea water got into fresh water habitats having severe impacts on the wildlife
- 1.5 billion litres of sewage was released into the Raritan River in New Jersey
- 90% of beaches in New York and New Jersey was damaged
- 1.5 millions litres of oil was spilt into Arthur Kill destroying wildlife habitats killing fish and birds
what were the social impacts of Hurricane Sandy on Cuba ?
- 11 people were killed
- there was no electricity or fresh water
- 17,000 homes were destroyed
- 226,000 homes were damaged
what were the economic impacts of Hurricane Sandy on Cuba ?
- total losses in Santiago area were US$50 million
- road to airport blocked so no tourists could come or go causing a loss in revenue
- US$2 billion in total losses
what were the environmental impacts of Hurricane Sandy on Cuba ?
- 2600 ha of banana crops were destroyed some of the crop was close to Maisi town
- in Santiago de Cuba trees were uprooted and lost all of their leaves
- coffee plantations in mountainous areas were swept away
- area close to the coast were flooded with beaches been swept away destroying wildlife habitats