Global Hazards Flashcards
What is the difference between a hazard and a disaster?
Hazards are possible dangers which could happen but a disaster is something that has actually happened
What is the difference between weather and climate?
Weather is day to day conditions of the atmosphere e.g. wind, rain, sun
Climate is the average conditions of a place e.g. temperature and rainfall
How does the Earth evenly distribute energy from the sun
Most of the energy enters the earth through the equator, this causes the air to heat up and rise. It then moves along the earth’s surface and cools down and heats up, this distributes the energy around the globe.
What is the climate like at the equator where the Hadley cells meet
Hot, low pressure and lots of clouds
What is the climate like where the Hadley cell meets the Ferrel cells
Quite hot, high pressure, very few clouds, cold at night
What is the temperature like where the Ferrel and Polar cells meet (The UK)
Low pressure, clouds and quite cold
What is the conditions like at the poles
High pressure, few clouds, cold
Why are the polar regions not warmed as much by the Sun as the Equator
Because the energy has to travel further through the atmosphere and there is more area being heated.
What is the Albedo effect
This is how much a surface reflects or absorbs the Sun’s rays.
e.g. polar ice has a high Albedo effect and reflects the heat. This makes the poles colder. Rain forests and oceans have low Albedo effects and absorb lots of heat
What is Cloud cover
Clouds reflect heat and at places where there are lots of clouds, the temperature is lower
What effects does the wind have
Surface winds move heat around the world
What are Ocean currents
Because water is fluid, ocean currents move heat easily
e.g. The UK is warmer than other countries on its latitude because it is warmed by the North Atlantic Drift.
It is a warmer current which originates in the Caribbean
What is the effect of Land and sea
On land, insulation is concentrated on the surface.
But at sea it reaches deeper because water is transparent
Water is slower to warm up but it stays warmer for longer
What is the effect of Altitude
Higher up, air pressure is lower, which makes temperature colder. They drop by about 1 degree every 100 metres in altitude
What causes wind?
Movement of air from places of high pressure to places of low pressure
Why does Antarctica frequently experience strong winds?
Because the large ice sheets which gently slope into the sea contribute to the wind speeds, Katabatic winds
Why does the change in relief lead to heavy rain?
Because the mountains cause the clouds up higher into the air which causes them to condense and collect a lot of water. This means that the clouds are heavy and it rains very hard.
What hazards could such heavy rainfall bring to this area of steep relief?
Flooding
Where do tropical storms form?
Over tropical oceans
What is a drought?
They are periods of time where there is much less precipitation in an area that is predicted
What is El Nino
El Nino events are related to weaker trade winds and lead to warmer than usual sea surface temperatures in the Pacific Ocean. They can cause drought in such areas as Australia and Asia.