hazardous earth - tectonic plates Flashcards
define lithosphere
the upper most layer of the earth - the top of the mantle and the crust
define asthenosphere
lower part of the earthβs mantle
how hot is the inner core
6000Β°C
how hot is the outer core
5000Β°C
how hot is the mantle
3800Β°C
how thick is the oceanic crust (km)
6-8 km
what is the oceanic crust made of
basalt
how thick is the continental crust (km)
30-50 km
what is the continental crust made of
granite
is the oceanic or continental crust denser
the oceanic crust is denser
which type of crust can be destroyed (continental or oceanic)
oceanic can be destroyed when two techtonic plates meet
what makes the core so hot
radioactive decay of some elements eg
uranium
what is the magnetosphere
a huge invisible magnetic field that surrounds the earth, protecting us from harmful radiation from space
what part of the earth produces the earthβs magnetic field
the outer core
what is pangea and how long ago did it exist
250 million years ago, the continents were once all joined together as one large supercontinent