These movements generally occur as a result of slippage along fault surfaces due to the release of frictional forces that build up along the fault. The rapid slip between two brittle blocks of rock creates a shock wave that is transmitted through the overlying rock to the surface where we feel it as an earthquake. A seismometer senses the vertical and horizontal motions of the ground resulting from the deep earth movement and displays these motions as squiggly lines on a seismograph. When you jump on the platform here, you are creating a shock wave that is measured by the seismometer and displayed on the seismograph. All rights reserved.
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