Question

define the following in your own words 1)Seismograph 2)Ritcher scale

Answer 1

1)an instrument used to measure ground movements caused due to earthquake.
2)it is used to measure the magnitude of the earthquake or how long it will be.

Answer 2

Richter scale
a numerical scale for expressing magnitude of an earthquake on the basis of seismograph oscillations

seismograph
an instrument that measure n record the details of earthquake