Earth structure Flashcards
what is the percentage of earth’s volume for crust, mantle?
crust: 1%
mantle: 80%
what is the crust made out of and its thickness?
- basalt and granite rocks
-70km
Mantle: thickness temperature
Mostly solid rock, 2.9000km thick, temp of up to 800°c to 3000°c
what is the core made out of and wht is
its depth n length N tempt
Iron and nickel, liquid outer and solid inner, 3.500km with temps from 3000° to 5000°
Why do plates move?
Convection currents, movement of heat in mantle, causing plates to be dragged the hot mantle material cools n sinks dragging plates along. Repeats. Slab pull force.
O-O plate divergence landforms
Mid Atlantic Ridge, volcanoes + seafloor spreading
Example of o-o divergence
North American plate and Eurasion plate
C-C divergence landforms
Block Mountains and rift Valley
CC plate divergence how is it formed
When the plate diverges or moves apart, it is stretched and causes fractures
what is O-O plate convergence
The denser plate subducts under the less dense plate, known as subduction zone. A depression is created which forms oceanic trench
Landform of O-O convergence
Volcanoes, oceanic trench,
Example of O-O convergence
Pacific plate and Philippines plate
what is C-C plate convergence
2 CC plates collide as they RESIST subduction as the plates r too buoyant
Example of CC convergence
Indian and eurasian plate, creating himalayas
Landform of CC convergence
Fold mountains, volcanoes
OC plate convergence landforms
Volcanoes, oceanic trench, fold mountains
Example of OC plate convergence
Australian plate and eurasian plate creating sunda trench n barisan mountains
Fold mountains formation
Convergent plate boundaries, compressional force causes layers of Dock to buckle and fold
Reasons for the movement of plate tech
Convection current cause the movement of material in the mantle as the core heats it up causing the material to expand, rise and spread out beneath the plates. This results in plates being dragged along to move away from each other. Hot mantle sinks as it cools. It heats up agn, cycle repeats.
Slap pull force
SPF occurs when dense sinking oceanic plate at subduction zones pulls the rest of the plate behind it.
