Transcript GCSE C1.7 - The Earth - School

The Earth
26-May-11
True or False?
1) The Earth is made up of the crust and
mantle.
2) The outer part of the Earth is cracked
into plates.
3) The UK is moving away from North
America.
4) The crust and upper part of the mantle is
called the lithosphere.
5) Mount Everest is getting taller because
the Earth’s crust is being squashed up by
moving plates.
True or False?
FALSE
1) The Earth is made up of the crust and
mantle.
TRUE
2) The outer part of the Earth is cracked
into plates.
TRUE
3) The UK is moving away from North
America.
TRUE
4) The crust and upper part of the mantle is
called the lithosphere.
TRUE
5) Mount Everest is getting taller because
the Earth’s crust is being squashed up by
moving plates.
Earth structure
The idea of a land bridge used to explain fossil evidence before
the theory of continental drift was accepted.
Two plates moving apart
Oceanic – continental plate boundary
Plate sliding past each other
Journey to the
centre of the Earth
(Imaginary!!)
24-Feb-08
Earth structure
C1b 6.1
What is below the surface of
the Earth?
Race to the core!
A team of scientific explorers are
racing to the core of the Earth. At
stake is a prize of £10 million and
the honour of winning. The team
has chosen to start drilling through
solid rock from a base in Cornwall.
This is one of the most difficult
explorations ever undertaken by
human beings - if they reach the
core they will have to put up with
temperatures almost as hot as the
surface of the Sun! Their progress
will be reported on the project
website for everyone to join in!
Distance from surface: 1 km
Temp: 55 C
Conditions: Solid rock,
mainly granite
1km
We have already drilled
down nearly 1 km through
solid rock and we’re about
to build our first rest
station. This will be a base
where we can start going
deeper.
We have been very pleased
with our diamond-tipped
drills. They are making
faster progress than we had
anticipated.
Distance from surface: 20 km
Temp: 400 C
Conditions: Solid rock, with
pockets of liquid
20km
It’s getting very hot outside
now. The rock is fairly
stable but we’ve had
problems with the pressure
that almost cracked our
hyper-strong tunnel. The
next rest station will be
very difficult to make.
Distance from surface: 120 km
Temp: 650C
Conditions: Solid rock, with
pockets of liquid
120km
We are inside the mantle
now. The rocks outside are
rich in iron and magnesium.
Even with the pressure they
are starting to become
more plastic - which means
they move around a bit but
are not yet liquid. Soon we
will have to switch to the
robot ship - we cannot go
much further ourselves.
Distance from surface: 2000 km
Temp: 800C
Conditions: Very thick liquid almost solid
2000km
We are deep in the mantle
now. The rock around us is
like a very thick liquid. We
have switched to the robot
ship so we can explore the
way forward from our base
in the crust. This is the area
where our project could fail.
The conditions are much
tougher than the early
astronauts faced on the
Moon!
Distance from surface: 3500 km
Temp: 5000 C
Conditions: Liquid rock, rich in
iron
3500km
We’ve reached the core!
We’re in the outer core
which is a liquid made of
iron-rich minerals - like
nothing you’ve ever seen
on the surface. Our little
robot probe ship is battered
and damaged - you can see
the quality of the images
we’re getting but our team
is ecstatic!
Distance from surface: 6000 km
Temp: 7000C
Conditions: Liquid rock, rich in
iron
6000km
OK, so this is a cheat! Our
robot probe cannot get this
far but it has scanners which
can ‘see’ a few hundred
kilometres in front of it. You
are looking at a picture from
the inner core. It looks like a
solid! The pressure stops the
rock from melting! The
temperature here is about
the same as the outer
regions of the Sun!
1 km
20 km
120 km
How deep
Crust have we
gone?
2000 km
Mantle
3500 km
Outer Core
6000 km
Inner
Core
Bristol
New York
If you start on the Earth’s
surface how far down would
you go if you travelled the
same distance as the distance
between London and:
Barcelona
Paris
The distance from London to:
Bristol =
200 km
New York =
5586 km
Barcelona =
1183 km
Paris =
343 km
Earthquakes
& volcanoes
24-Feb-08
Mount St Helens, USA
1980
Alaska 2006
Volcanic eruptions – warning signs
1) Increasing temperature of volcano (due to
moving magma underground)
2) Rising ground level around the volcano due to
the build up of magma
3) More sulfur dioxide (SO2) given out
You know where it is going to happen, but not
exactly when – issue of whether to evacuate or not!
Japan 2011
Pakistan 2005
Japan 1964
Colombia 1999
Earthquakes – warning signs
1) Pre-shocks (small earthquakes)
2) Water levels in wells fall
3) Some animals act strangely
You don’t know exactly where or when it will happen
though!