Audio Transcript Auto-generated
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Hello, everyone. So today I will be talking about
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India Lemon.
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She was born in May 13, 18 88 and
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died February 21 1993.
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Danish Seismologist was best known for her discovery of the inner core of the earth
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in 1936 by using seismic waves data.
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Yeah.
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All right. So how can we find out what's happening deep inside the earth?
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The temperatures are too hot pressures,
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too extreme and distances too vast to be explored by conventional pros.
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So scientists rely on
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seismic waves, shocks, waves
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generated by earthquakes and explosions that travel through the earth
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and across the uh its surface to reveal the structure of the interior of the planet.
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Thousands of thousands of earthquakes occur every year and each
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one provides a fleeting glimpse of the earth's interior.
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Seismic signals consist of several kinds of waves.
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Those important for understanding the earth's interior are.
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The first one is P waves, primary or compressional waves.
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The second one is S waves,
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secondary or sheer waves which travel through
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solid and liquid material in different ways.
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Sorry, skip one.
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So the seismograph,
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so the
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seismograph
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was invented in 18 80 to detect and record
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seismic waves movements. By the end of 18 eighties,
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seismic stations had been established all over the world. At the time,
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physicists believed that the earth was composed of liquid
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of a liquid core surrounded by solid metal
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which was in turn surrounded by crust. These layers were separated by
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abrupt
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density changes
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in the earth known as
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discontinue teeth.
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So thank you in
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the lemon for the discovery of the inner core and the outer core.
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Thank you. So for so much.