Flashcards in Hazardous Earth Deck (52)
Why is it dry at the poles?
It is dry as there is high pressure so the air sinks and holds its moisture
What are the sun's rays like at the poles?
They are scattered so they are less concentrated so there is less evaporation
Why is it wet at the equator?
Because there is a low pressure meaning the air rises then cools and condenses
What are the sun's rays like at the equator?
The sun's rays are concentrated causing lots of evaporation
Name the pressure cells
Hadely cell, Ferrell cell and Polar cell
What are trade winds?
Trade winds are strong winds that meet at the ITCZ
What is the ITCZ?
The Inter-Tropical Convergence Zone is an area of low pressure between the two Hadley cells
Name some natural causes of climate change
Volcanic eruption theory, sunspots
Name some evidence of climate change
Tree rings and ice cores
Explain tree rings
Trees grow a new ring every year and if the conditions are good (warm and wet) the ring will grow wide. And if the conditions are poor (cold and dry) the ring will be narrow. Scientists can then gather what the climate last year was like.
Evidence of global warming
Sea level rising
Explain sea level rising
The ice caps melt and cause levels to rise as the water has been deposited into the sea. 1998 the sea level change was 5mm an by 2013 it was 60mm. Also the thermal expansion causes the sea to heat up and its particles to expand increasing the volume.
Name two ocean currents
North Atlantic Drift and Labrador Current
Why are coastal areas warmer than inland areas in the winter?
Since the sea keeps its heat longer as it is a liquid so it cools down slower
Effects of climate change
Glaciers as they have been retreating due to the increase in temperature. Greenland's ice sheet is shrinking and 90% of Antarctica's region are retreating.
How will this affect people?
As it is believed the Gulf Stream could be diverted meaning people in Western Europe would be much cooler
Where are tropical cyclones found?
5-30degrees north and south of the equator
What temperature does the ocean need to be for one to form?
How do tropical cyclones form?
Cyclones originate over oceans of 26degress or more; they start when strong winds drift over warm water. The warm air and ocean surface combine and rise due to the low pressure and lots of evaporation. Trade winds blow causing it move and the coriolis force spins it.
Look at book for cyclone diagram
Name impacts of Alia
750,000 left homeless
Loss of animals meant loss of dung so loss of cooking fuel
Flooding caused freshwater to become contaminated
Name impacts of Katrina
1200 people drowned
1million people were made homeless
80% of city evacuated
Lots of looting afterwards
Over 2/3 became submerged
Many offshore oil facilities destroyed
Name Earth's structure
Asthenosphere(upper mantle)( partially molten)
Outer core (liquid, iron and nickel)
Inner core (solid and nickel)
What is a divergent boundary?
When oceanic plates move apart forming new oceanic crust. Found on the North American plate and Eurasian plate
What is a destructive boundary?
When the oceanic plate is subducted by the continental plate an is found on the Nazca plate and South American plate
What type of volcano is found at the destructive plate?
Composite- really explosive
What is a collision boundary?
When continental plates collide and create fold mountains such as the Himalayas. Found on the Indian plate and Eurasian plate
What is a conservative boundary?
When two continental boundaries move alongside and pressure is built up and one will jerk forward sending shock waves to the surface, triggering an earthquake. Found on the North American pate and Pacific plate
What is a hotspot volcano?
A hotspot volcano is a volcano that forms in a centre of a plate