Explain what seismographs measure and what geologists mean by the terms magnitude, intensity, and hazard.

Answer: Definition Seismographs are the instruments which record earthquakes.

A seismograph is a device for measuring the movement of the earth, and consists of a ground - motion detection sensor, called a seismometer

Magnitude measures the energy released at the source of the earthquake. Magnitude is determined from measurements on seismographs.

Magnitude and Intensity measure different characteristics of earthquakes ... Magnitude is determined from measurements on seismographs. Intensity measures the strength of shaking produced by the earthquake at a certain location. Intensity is determined from effects on people, human structures, and the natural environment.