Topic 2 Flashcards
(28 cards)
What can the Earths crust be divided into
Oceanic crust and continental crust
Name the three layers of the earth
The crust mantle and core
What is the crust
The solid outer part of the earths crust
What is the mantle
An area of hot molten rock beneath earths crust.
Name the two parts of the core
Inner and outer core
How thick is the crust
10-70km thick
How thick is the mantle
2800km
Outer Caro thickness
2250
Inner core
1250 km thic
How thick is oceanic crust
Less than 10km
Name all the tectonic plates
Northern American plate Eurasian plate Arabian plate Caribbean plate Juan de Fuca plate Cocos plate Pacific plate Nazca plate South American plate African plate Indian plate Indo-Australian plate Antarctica plate Scotia plate Philippine plate
How fast do tectonic plates move
As fast as your finger nails grown , almost 3 cm a year
Explain convection currents
Heat from earths core causes circular movements in the mantle
Where are some of the worlds most active volcanos
The ring of fire
Where do volcanos form
At places where plates move apart
How do colliding plates cause volcanos
It occurs when a recto Jc plate slides under another plate, it begins to melt back into mantle . It works itself through the crust the. It erupts as a volcano
Explain how earthquakes happen
Earths tectonic plates grind against each other creating shock waves that vibrate through Earths crust . The shock waves cause the ground to shake.
Explain faults
Convection currents in the magma cause pressure to build up at plate margins.
Name 6 effects of an earthquake
Tsunamis Buildings collapse and crush people Can start fires after the earthquake People are left homeless Polluted water and dead bodies spread disease easily
What are the variables that change the ways people are affected during earthquakes
How many people live in the area
Quality of buildings
How well they are prepared
Availability of people who can rescue people
Describe a high risk community for earthquakes
Urban areas with lots of people People who live close the the sea where earthquakes occur may experience tsunamis Places with poorly made buildings Places with poor rescue plans Bad communication
List five ways to reduce the impact of an earthquake
Good equipmentment to cope with earthquake damage Well trained rescue teams Doctors nurses medical supplies Emergency plans to cut of gas Warning systems
What is a flood?
It is when there is too much water on the land
List a few things that how the things in the environment help to cause floods.
Long periods of very heavy rain fill up rivers and dams
Steep slopes cause rainwater to flow off the land quickly
If fires have destroyed the vegetation, water flows quickly into rivers off the bare ground
If animals have eaten all the grass water flows quickly into rivers
Tsunamis and storms can flood coasts
