Question

question 15
when will the first earthquake waves arrive at a seismograph station?
o a short time before the earthquake occurs
o at the same time that an earthquake occurs
o a short time after the earthquake occurs

question 16
what is a seismograph?
o an instrument used to predict earthquake waves
o an instrument used to create earthquake waves
o an instrument used to record earthquake waves
o an instrument used to analyze earthquake waves

Explanation:

Question 15

Earthquake waves (seismic waves) take time to travel from the earthquake's origin (epicenter) to the seismograph station. They start moving when the earthquake occurs, so they arrive a short time after the earthquake occurs.

A seismograph is a device that records the ground - motion caused by earthquake waves. It does not predict (we don't have reliable earthquake prediction instruments yet), create, or analyze (the initial function is recording) the waves in the primary sense.

Answer:

a short time after the earthquake occurs

Question 16