How does a seismograph record earthquake waves?
A seismograph is an instrument used to detect and record seismic waves produced by earthquakes. Here is how it works:
1. The seismograph consists of a base or frame that is securely anchored to the ground. On top of the base, there is a sensitive mass that is suspended in such a way that it can move independently of the base.
2. Attached to this mass is a pen or pen-like device that rests on a rotating drum covered with paper. As the mass moves in response to ground shaking caused by an earthquake, the pen also moves along the drum, creating a zig-zagging line on the paper.
3. The drum rotates continuously, allowing the pen to record the movement of the mass over time. This creates a seismogram, which is a visual representation of the seismic waves produced by the earthquake.
4. Different types of seismic waves, such as P-waves, S-waves, and surface waves, travel at different speeds and produce distinct patterns on the seismogram. By analyzing the characteristics of the seismic waves recorded on the seismogram, seismologists can determine important information about the earthquake, such as its magnitude, location, and depth.