Download The Earth resources complete

RHS Chemistry department
Name ………………………………………………………………………………………………………
C1.7 Earth and atmosphere
Class …………
Date ………………….
The Earth’s Resources
• The Earth's crust, oceans and atmosphere are the ultimate source of minerals and
resources — we can get everything we need from them.
• The Earth’s resources:
• Metals like gold, silver copper e.g. and iron e.g. can be mined from the
Earth's crust.
• We can get salt from the Earth's oceans. This is useful for:
making chemicals; food preservative and flavouring
• Gases like oxygen and nitrogen can be extracted from the air
Tectonic Plates
• The crust and the upper part of the mantle [called the lithosphere] are cracked into
a number of large pieces called tectonic plates These plates are a bit like big rafts
that ‘float' on the mantle.
• The plates don't stay in one place though. That's because the convection currents
in the mantle cause the plates to drift. The convection currents are caused by
radioactive processes in the core that release huge amounts of heat energy
• The map shows the edges of the plates as they are now, and the directions they're
moving in (curved arrows).
RHS Chemistry department
C1.7 Earth and atmosphere
 Most of the plates are moving at speeds of a few centimetres per year relative to
each other. Occasionally, the plates move very suddenly, causing an earthquake.
Volcanoes and earthquakes often occur at the boundary between two tectonic
plates
Predicting earthquakes
• Tectonic plates can stay more or less put for a while and then suddenly lurch
forwards. Earthquakes are impossible to predict accurately because we can't see
what's happening deep below the surface but scientists are trying to find out if
there are any clues that an earthquake might happen soon — things like strain in
underground rocks.
• Scientists can use these clues to predict that an earthquake will happen, but these
predictions are sometimes ignored by local people and governments because:
• Even with all their clues scientists can only say that an earthquake's likely to
happen, not that it definitely will happen. Scientists make many earthquake
predictions every year and not all of them are right.
• If the earthquake does happen, it's impossible to predict exactly when.
The earthquake could happen months after the initial prediction.
• There's no way to accurately predict the severity of the earthquake. Many
earthquakes cause little or no damage.
• Scientists can't accurately predict exactly where the earthquake will happen
— it could be miles away from where it was initially predicted to happen.
• There's no way to stop an earthquake, so the only way that people can
respond to a predicted earthquake is to evacuate This is expensive and very
inconvenient, so people don't want to do this unless they are sure that the
earthquake will happen imminently and where they live and will be strong
enough to cause serious damage and put their lives at risk.