Question

which statement describes a seismograph? it has a flat graphing surface. it is used to locate an earthquakes focus. it uses a needle on graph paper to measure seismic wave activity. it measures data used to find the difference between the arrival times of surface waves.

Explanation:

A seismograph is an instrument that records seismic - wave activity. It has a pen or needle that moves across graph paper as seismic waves are detected, tracing out the motion of the ground.

Answer:

It uses a needle on graph paper to measure seismic wave activity.