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How do geologists find out about the Earth's crust?
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Until early in the 20th century, the only way geologists could find out about the Earth's crust was to examine rock samples. This involved breaking them off with a hammer (1) and analysing their chemical composition. Today, they can also drill deep into the crust (2) to collect samples; make artificial earthquakes (3) and record the shock waves (4) in order to map the layers of rock; and use aerial photography (5) and satellites (6) to give us new information about the Earth's surface. | | Geologists use advanced modern technology to find out more about the Earth's crust. |
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Previous:
Back
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Book:
1001
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Section:
Earth
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Chapter:
Rocks and Minerals
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