Hazardous Environments

Question 1

Theory of PLATE tectonics

Answer 1

The theory put forward the idea that the LITHOSPHERE - the outer layer of the earth consisting of the CRUST and the UPPER MANTLE is divided in to a number of TECTONIC PLATES

Question 2

What are plate margins and boundaries ?

Answer 2

Where the earths oceanic or continental crustal plates come into contact with one and another . They are zones where the plates can undergo great stress and change.

Question 3

Define continental crust

Answer 3

it is older, lighter, cannot sink and permanent. It is typically 200km thick

Question 4

Define Oceanic Crust

Answer 4

It is younger, heavier, sinks. Continually being formed and destroyed . Typically 100km thick