Question: in what order do the 3 types of seismic waves arrive at a seismograph?
Answer: Earthquakes produce three types of seismic waves: primary waves, secondary waves, and surface waves. ... 
The fastest seismic waves are called primary waves, or P waves. ... 
Secondary waves are the second seismic waves to arrive at any particular location after an earthquake, though they start at the same time as primary waves.