A seismograph measures motion in the Earth and produces a seismogram, which can reveal valuable information about earthquakes. P and S waves are two types of waves studied on a seismogram, with P waves usually recorded first and S waves having more amplitude. Seismograms can also reveal the extent and distance of seismic waves, as well as the proximity of an earthquake to the surface. Modern seismograms are produced digitally and can be transmitted long distances for analysis.
A seismograph is a machine used by scientists to measure motion in the Earth. The reading of this machine is called a seismogram. It can reveal valuable information such as the location or severity of an earthquake.
The results on a seismogram are shown by lines. When there is no activity, the reading will reveal a long, straight line. When motion is detected, you will see a long line of lines going up and down. These lines represent motion in the Earth, also known as seismic waves. Two types of waves studied on a seismogram are P and S waves.
P waves, also known as thrust waves, result from forward motion. Torsion waves, often called S waves, represent the spiraling motion of particles as they twist between internal structures. P waves are usually the first to be recorded on a seismogram because they travel the fastest. S waves usually have more height, or amplitude, than P waves. The amplitude of the waves can help reveal information about an earthquake’s magnitude.
A seismogram can reveal the extent to which seismic waves from the seismograph have occurred. This is often shown when the reading has P waves but no S waves. This generally means the movement was far away. A more accurate indication of distance may be available when the time between the recording of P and S waves is calculated. In many cases, several seismograms originating from various locations are compared for this purpose.
A seismogram often reveals how close an earthquake occurs to the surface. This is made evident by recording surface waves, which are slower than S and P waves. These can be identified because there is usually more space between them than between other types of waves. They are also often the largest marks on the seismogram.
Some of the signs on a seismogram may not be related to an earthquake. Some signs may be micro-earthquakes. This is the movement that a seismograph records, but which is caused by other factors such as explosions or ocean waves.
Seismograms have changed over time. These readings were once recorded using pen or pencil and paper or a beam of light and photosensitive paper. Modern seismograms are most commonly produced digitally. Results are often transmitted long distances from one point where they are recorded to another point where a professional analyzes them.
Protect your devices with Threat Protection by NordVPN
