What is a seisgrahf?

Answer 1

A seismograph is a tool scientist uses to measure earthquakes.

Answer 2

It seems like there may have been a typo. Did you mean 'seismograph'? If so, a seismograph is a device used to detect and record the intensity and duration of earthquakes. It typically consists of a suspended mass that moves with the ground vibrations, producing a record called a seismogram.