Topic 1 - Hazardous Earth Flashcards
What are the three global atmospheric cells called?
Polar (top), Ferrel (middle) and Hadley (bottom).
What does warm and cool air do?
Warm air rises and cool air falls.
What does air do in terms of pressure?
Warm air rising a creates a low pressure belt, and cold air falling creates a high pressure belt.
What are ocean currents?
Large scale movements of water that transfer heat energy from warmer to colder regions.
How does the tropical climate form?
Rising air from the two hadley cells meeting causes low pressure and lots of rainfall, temperature is hot all year round.
What is climate change?
Any significant change in the Earth’s climate over a long period of time.
Give an example of a natural cause of climate change.
Volcanic activity - eruptions eject masses of material such as ash, particles reflect sun’s rays and Earth’s surface cools.
When do tropical cyclones develop?
When the sea temperature is over 26.5oC and the difference in wind speed is low.
What is a storm surge?
A large rise in sea level caused by low pressure and high winds.
How do people measure windspeeds of cyclones?
Using the Saffir-Simpson scale.
When and where was Hurricane Katrina?
29th of August, 2005, South east USA.
What category was Hurricane Katrina? and Statistics?
It was category 3 at landfall. More than 1800 people were killed, and 300,000 houses were destroyed.
What is the core made out of?
Iron and nickel, inner (solid) and outer (liquid) - temp. ranges from 4400 - 6000oC
What are both the mantle and the crust made out of?
Silicon-based rock
What are the two types of crust?
Oceanic and Continental.
What happens at a convergent plate boundary?
Oceanic meets continental, the denser oceanic is forced down then destroyed by mantle - often forming volcano.
What happens at a divergent plate boundary?
Two plates moving away from each other and magma rises.
What happens at a conservative plate boundary?
Two plates moving sideways past eachother - crust is neither created or destroyed.
Name three characteristics of composite volcanoes?
Occur at convergent plate boundaries, volcanoe is steep, explosive, layer of ash, thick and sticky lava.
Name three characteristics of a shield volcano?
Not explosive, lava is runny, wide and stumpy, only occur at divergent or hotspots.
How do people monitor or predict an earthquake?
Seisometers - monitor vibrations in the earth’s crust.
How do people predict an eruption of a volcano?
Thermal imaging cameras - detect changes in temperature, if temp. increases, it will erupt.
Give two examples of long-term planning for a tectonic hazard?
Buildings can be designed to withstand earthquakes, people can be educated to know what to do, planned evacuation routes.
Give two examples of short-term relief after disaster?
Provide temporary supplies, food and water, rescue people, recover dead bodies to prevent the spread of disease.
What is a hotspot?
Found away from plate boundaries, hotspots are where volcanoes can form in the middle of tectonic plates.
How are earthquakes measured?
The moment magnitude scale, which measures the energy released by an earthquake.
How are earthquakes caused?
Earthquakes are caused by tension that builds up at all three plate boundaries.
How are tsunamis formed?
Underwater earthquakes cause the seabed to move, which displaces water. Waves spread out from the epicentre of the earthquake.
What are the two countries that you have studied, in terms of tropical cyclones?
Hurricane Katrina - USA, good prediction, defences failed, 1800 killed, 300,000 houses destroyed.
Cyclone Nargis - Myanmar, no prediction, warning only 48hours before, no defences, 140,000 killed, 450,000 homes were destroyed.
