There are several ways: a pen drawing an ink line on paper revolving on a drum a light beam making a trace on a moving photographic film electromagnetic system generating a current that is recorded electronically or digitally on tape
Seismograms are the records (paper copy) produced by seismographs used to calculate the location and magnitude of an earthquake. They show how the ground moves with the passage of time.On a seismogram, the HORIZONTAL axis = time (measured in seconds) and...
An earthquake cannot occur at depth of 0 km. In order for an earthquake to occur, two blocks of crust must slip past one another, and it is physically impossible for this to happen at the surface of the earth. So why do we report that the earthquake...
A seismometer is the internal part of the seismograph, which may be a pendulum or a mass mounted on a spring; however, it is often used synonymously with "seismograph". Seismographs are instruments used to record the motion of the ground during an EQ--...
It is relatively easy to acquire the necessary materials and build your own seismometer. The links here are to various sources with information on how to build a seismometer. They range from very simple and inexpensive to sophisticated and pricey.Learn...
The earliest seismoscope was invented by the Chinese philosopher Chang Heng in A.D. 132. This was a large urn on the outside of which were eight dragon heads facing the eight principal directions of the compass. Below each dragon head was a toad with its...
When an earthquake occurs, it releases energy in the form of seismic waves that radiate from the earthquake source in all directions. The different types of energy waves shake the ground in different ways and also travel through the earth at different...
The Richter scale is not a physical device, but a mathematical formula. The magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded on a seismogram at a certain period.Learn more:Magnitude LinksIntensity Links 
Acceleration is the rate of change in velocity of the ground shaking (how much the velocity changes in a unit time), just as it is the rate of change in the velocity of your car when you step on the accelerator or put on the brakes. Velocity is the...