Our changing planet
1aMatch a word from the list with each of the labels A, B, C and D on the diagram of the Earth. atmospherecorecrustmantle
A= core B= mantle C=crust D=atmosphere
bFrom which parts of the Earth do we get all of our raw materials? Aatmosphere, core and crust
Batmosphere, crust and oceans
Catmosphere, core and mantle
Dcore, mantle and oceans
Alfred Wegener (http://www.bbc.co.uk/schools/gcsebitesize/science/aqa/oils/changesrev2.shtml) 2aAbout one hundred years ago there was a scientist called Alfred Wegener. He found evidence that the continents, such as South America and Africa, had once been joined and then drifted apart.
Use the diagram to suggest two pieces of evidence that could be used to show that the continents had once been joined.
The same Sedimentary rock was found on both continents containing fossils and also the shape of the east side of south America and the west side of Africa fit like a jigsaw puzzle.
Evidence for plate tectonics (http://www.bbc.co.uk/schools/gcsebitesize/science/aqa/oils/changesrev3.shtml)
bAbout fifty years ago, new evidence convinced scientists that the Earth’s crust is made up of tectonic plates that are moving very slowly. Give two pieces of evidence that have helped to convince these scientists that the tectonic plates are moving.
The movement and separation of continents and Earthquakes are a result of plate movement. They are the sudden release of energy built up when plates do not move smoothly past one another
Plate tectonics (http://www.bbc.co.uk/schools/gcsebitesize/science/aqa/oils/changesrev2.shtml)
cDescribe as fully as you can what causes the Earth’s tectonic plates to move.
Right below the rigid outer layer of the earth called the lithosphere, there is molten rock. Since this liquid is denser then the lithosphere pieces itself, the earth's tectonic plate’s float on top the liquids circulation of magma. But this happens at a very slow speed moving a few centimetres a year
Composition of the Earth's atmosphere (http://www.bbc.co.uk/schools/gcsebitesize/science/aqa/oils/changesrev4.shtml)
Evolution of the atmosphere
3aIn the Earth’s atmosphere the percentage of carbon dioxide has remained at about 0.03% for many thousands of years. The graph shows the percentage of carbon dioxide in the Earth’s atmosphere over the last 50 years. [pic]
iWhat was the percentage of carbon dioxide in the Earth’s atmosphere in 1965?
iiWhat change has happened to the percentage of carbon dioxide in the Earth’s atmosphere over the last 50 years?
There has been a massive increase in the amount of carbon dioxide and this shows a strong positive correlation
iiiSuggest one reason for this change.
The increase could be because of many rainforests and woodlands are being destroyed and plants which consume carbon dioxide in the process of photosynthesis, where along with sunlight and water convert this carbon dioxide to oxygen and water
ivWhy does this change worry some people?
As this green house effect is getting worse every year this greenhouse effect causes trouble by raising the temperature of the planet. The actual rise is not very much, but the Earth's ecosystem is very fragile, and small changes can have large effects. This also causes global dimming
There are different theories about the Earth’s early atmosphere. bSome scientists believe the Earth’s early atmosphere was mainly carbon dioxide and water vapour....