CHAPT 8

MOUNTAIN

A area of high ground.

usually 6oom and above,

eg. mount everest, mount himalayas

HILL

Area of high ground

rounded in shapes

has gentle slopes

VALLEY

Low area of land

Between hills or mountains

PLAINS

Broad, flat and low area of land.

PLATEAU

Raised area of land

Flat broad top

Has steep slopes.

MANTLE

2900 KM

80% Of earth's volume

2000 degrees c.

top layer is semi-molten/liquid

CORE

5000 degrees c.

inner part of it is solid

because of the great pressure and weight exerted on the core by the outer layer of earth/

CRUST

6 to 7 km thick

solid

made up of plates that float on semi-molten/liquid(magma)

INTERNAL FORCES THAT CREAT LANDFORMS

The earth's crust is always moving

movement of the plates on the semi-molten/liquid is called crustal movement

when plates move, the might slide past, pull apart from or push towards each other.

mountains and volcanoes are created by processes occuring within the earth on the earth's surface. (FOLDING AND VULCANICITY)

FOLDING

two plates collide and and some of the layers of rock that makes up the earth's crust will buckle and form folds.

the amount of foldings can be so little that it is hardly noticeable or it can be so large that a mountain is formed as a result.

eg. himalayas in nepal, mount everest, alps in europe, mount kinabalu(sp?)

VULCANICITY

the temperature below the earth's crust is so hot that it causes part of the mantle to melt and molten mantle is called magma. this magma pushes its way through cracks which are found on plate boundaries

the process whereby magma and other materials reach earth's surface is called vulcanicity. outpouring if lava is called eruption happens due to releaso of bulit up pressure of gases below earth's surface.

VOLCANOES

consists of vent, pipe, crater and cone

VENT

opening on earth's surface.

PIPE

channel that allows the magma to rise up to the top of the volcano during eruption.

CRATER

bowl shaped opening where volcanic materials like ash and lava are released.

CONE

shape of the volcano

built up by ash and lavaa released from a number of eruptions