Tectonics Flashcards
How deep is the earths crust
100km deep
What are the types of crust
Oceanic and Continental
Why do tectonic plates move?
The convection currents from deep in the earth, gravity may play a part
What happens at a constructive plate margin?
Constructive plate margins move apart and new crust is formed as magma rises to the surface
What happens at a destructive plate margin?
Where plates are moving towards each other the denser oceanic plate sub-ducts underneath the the less dense continental plate as gravity pulls the oceanic plate into the mantle
What is the inner most layer of the earth
Inner core
2nd inner most?
Outer core
2nd layer of the earth?
Mantle
Outermost layer of earth?
Crust
Where is tectonic activity like earthquakes and volcanoes most common?
Plate boundaries or fault lines
How many major plates are there?
7 major plates and several minor
(Pacific,Nascar, Antarctic, South American, scotia, Caribbean, African, North American, Eurasian, Arabian, Indian, Australian, cocos and the Philippine)
What happens at a conservative plate boundary?
Where plates slide past each other (opposite or same direction) BUT AT DIFFERENT SPEEDS. Eventually friction causes a sudden movement causing a shockwave and earthquake
What is the difference between the focus and the epicentre
The focus is the exact location in the earth of the earthquake while the epicentre is the point directly above the focus on the surface
One reason why people live in hazardous areas?
Large earthquakes and eruptions don’t happen very often
Another reason why people live in hazardous areas?
People living in poverty may focus on other issues e.g food, water or shelter
