What is seismology?

Seismology

Seismology is a study of the motions of the Earth's crust. Earthquakes are the most well known of these motions, but there are places where the crust is in motion all the time. Plate tectonics involves seismology, because the motion of plates relative to each other is what causes many earthquakes. A seismograph is a device for measuring such motions, which consists of a weight suspended from a point, and a rotating drum. The weight has a marking pen, or stylus, attached to it, which draws a line an the drum. As the drum turns, it raises or lowers, so that the trace does not overlap. When an earthquake hits, the suspended weight does not move very much, because of its inertia, so the trace on the drum, which is moving up and down from the waves of the earthquake, shows peaks and valleys. Interpreting these traces, to determine the amplitude of the earthquake, is what the science of seismology is specifically. Seismographs are so sensitive that some can measure earthquakes on the other side of the globe, explosions, and meteorite impacts.

Seismographs are one of the primary tools of telling what is happening in the ground below us, and in trying to predict when an earthquake will occur. They are also used in monitoring volcanoes, which create motions detected by the seismographs such as harmonic tremors, which is when magma is moving under the ground.

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