Restless earth lesson 1
Post on 19-May-2015
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Starter ActivityStarter Activity
On a piece of paper quickly On a piece of paper quickly draw a cross section of an draw a cross section of an
apple, peach or egg to apple, peach or egg to show the different layersshow the different layers
Key Ideas we’ll be covering in this Key Ideas we’ll be covering in this unit:unit:
–How and why do Earth’s tectonic plates move?
–What are the effects and management issues resulting from tectonic hazards?
Today’s Learning Objectives:Today’s Learning Objectives:1.What is the structure of the Earth? 2.What evidence can we use to work
out what the layers of the Earth are like?
c/w 27th January
Convection Currents
Inside the Earth, the source of the heat is the extremely hot core. This heat from the interior rises toward the surface of the Earth. It causes liquid rock in the mantle to move with it.
Hot and less dense liquid rock moves upward. Cool heavy rock sinks downward. This circular movement of matter is known as convection. Convection occurs within the liquid rock of the lithosphere’s mantle.
http://education.sdsc.edu/optiputer/flash/convection.htm
• Scientists believe that convection in the mantle is the reason why the crustal plates move. The plates ‘ride’ on convection currents. The plate motions, of course, result in volcanoes, earthquakes and mountain building. Convection caused Pangaea to break up. The convection currents pushed the continents to where they are today.
Plate movements have led to continental drift. 225 million years ago all the land masses were fused to form a super-continent - Pangea.
200 million years ago Pangea began to move apart to form two great land masses - Laurasia and Gondwanaland.
About 135 million years ago it was possible to make out land masses that looked more like those we see today.
For example it is possible to see how South America and Africa were drifting apart to form separate continents.
Pangea has now separated to form the Pangea has now separated to form the continents we know today.continents we know today.
The continents are made of “continental The continents are made of “continental
crust” and the oceans rest on “oceanic crust”.crust” and the oceans rest on “oceanic crust”.
But what are the thick black lines?
Direct Evidence that the Earth is structured in layers
This is evidence that can be seen on the Earth’s surface
For instance rock samplesAnother example is volcanic evidence,
such as volcanic gases and volcanic materials
This is evidence which comes from sources outside the EarthFor example, meteorites come from space but may be like rocks found at the
centre of the Earth (in the core)Earthquakes also help us understand the structure of the Earth. For example, patterns produced by earthquake waves indicate there are differences in the composition of the centre of the Earth
Indirect Evidence that the Earth is structured in layers
Class WorkRead Pages 8-10 in the green textbook.Use the information from these pages to complete the boxes on the A3 factsheet
Homework
Due next lesson Obtain a detailed cross section of the earth labelled with all the
key words. Include: distances, temperatures, names, etcYou may search on Google for this but make sure you
customise it to meet our needsComplete the convection currents diagram box on the right of
the sheet using p12 of your purple textbook.
Key VocabularyLithosphere Tectonic PlatesAsthenosphere Continental CrustOceanic Crust MantleOuter Core Inner CoreMeteorites GraniteBasalt
TASKSelect 4 words from the list but one has to be an “odd oneout”. Swap the 4 words with a friend. See if they can tell which is the odd one out. Get them to give a reason why it doesn’t match!
Key IdeasThe Earth is composed of layers with distinguishing
characteristicsThe Earth’s crust is divided into the continental and oceanic
crustThe crust can be identified by different types of rock: granite
and basaltThe asthenosphere has an important role in the movement of
tectonic platesEarthquake waves help us to understand the different
characteristics of the layers of the earthMeteorites help us to understand what the Earth’s core is
made of
How well can you...Define or explain today’s Key Vocabulary?Describe the different layers of the interior of
the Earth?Explain what evidence supports the theory
that the Earth is structured in layers?Understand the difference between direct
and indirect evidence?
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