C2c Does The Earth Move?

The Earth is as a sphere with a thin rocky ___________,

surrounding the _____________ and the ____________.

The Core This is made up from the inner core and the outer core

The Earth’s core contains _____________.

____________________________ reactions take place in the core which create

a lot of ______________ energy. As a result, the mantle stays molten.

The Mantle The mantle is the zone between the crust and the core.

It is relatively _____________ and ____________ just below the crust but hot

and non-rigid and so able to _______________ at greater depths.

Liquid rock is called _____________________.

The Lithosphere The lithosphere is made from the _______ and the outer part of the ______

It is made up from two types of tectonic plates:

1. _______________ plates (under oceans) most dense

2. _______________ plates (land) least dense

The lithosphere is relatively cold and rigid.

Tectonic plates are found on _______________ of the mantle because they

are ________________ dense than the mantle.

How do we know that tectonic plates move?

How do tectonic plates move?

Nuclear reactions in the core generate a lot of ______________ energy. The rock particles in the magma get hot, vibrate____________ and push

each other apart. This makes the rock __________ dense so it rises. As the rock rises towards the crust it ___________ energy, cools down and

particles move _______________ together. This makes the rock __________ dense so it sinks back towards the core.

The __________ and _____________ on the

east coast of South America are the

____________ as those on the west

coast of Africa which suggests that

they were once joined.

We call these ________________________ currents.

Earthquakes and Volcanoes

The movement of tectonic plates results in __________ activity and ___________

The diagram above shows the boundaries of the tectonic plates and the directions that they are moving in.

The diagram above shows all the regions of volcanic activity and earthquakes – note that the patterns are almost identical i.e. most volcanoes and earthquakes happen on plate boundaries

Volcanoes

Some of the rock on the Earth’s surface has been formed

by volcanic activity.

Molten rock (magma) can find its way to the surface through

_____________ in the crust.

Molten rock under the Earth’s surface is called _______________.

Molten rock that erupts from a volcano is called _______________.

When molten rock cools down it forms ________________________.

Some volcanoes give runny lava and some give thick lava violently and

catastrophically.

Some people choose to live near volcanoes because volcanic soil is very

_________________ (good for growing crops).

Higher Level Theory

Magma from the mantle must have a lower density than that of the crust

in order to rise through it.

Collision between oceanic and continental plate leads to _________________

and partial remelting (oceanic goes underneath continental).

Igneous Rocks The size of the crystals in igneous rocks depend on how ______________

the rock cools.

Magma that cools under the surface

cools __________ and forms large

crystals

e.g. granite

Molten rock that cools ____________

has very small crystals. e.g. lava,

basalt

Magma has different compositions and depending on what it is made

from depends on what sort of lava and explosion results:

Small (fine) Crystals Large (coarse)

Crystals

Iron-rich

‘runny’ lava and fairly safe in an eruption

Silica-rich

explosive reactions produce pumice, volcanic ash and “bombs” of magma

Geologists study volcanoes to be able to predict future eruptions and to

reveal information about the structure of the Earth they are now better at

predicting volcanic eruptions but not with 100% accuracy.

Think about and be prepared to answer questions on:

The problems encountered when studying the structure of the Earth and why opinions may vary greatly between different geologists.

Rock Types

Igneous Rock (e.g.basalt and granite)

Formed from molten rock cool – see previous notes

Sedimentary Rock (e.g.) limestone

When rocks weather the small pieces are washed by rivers to the sea.

Layers of sediment build up and a high ________________ causes the sediment

to cement together.

We call this sedimentary rock. It is ______________, _____________ and contains

___________________.

Metamorphic Rock e.g. marble, slate

If sedimentary or igneous rock is subjected to high ______________________

(near volcanoes) or high __________________ (near tectonic plate boundaries),

the rock can be __________________/change shape.

Limestone becomes _____________________ when it is heated

Mudstone (sedimentary) becomes ______________ (metamorophic) under high

pressures.