Strong earthquakes produce P-waves with which combination of amplitude and frequency?

Strong earthquakes produce P-waves with which combination of amplitude and frequency?

• A. Low amplitude and high frequency
• B. High amplitude and high frequency
• C. High amplitude and low frequency
• D. Low amplitude and low frequency

Answer: (C)

Strong earthquakes release a lot of energy, and the rupture lasts longer over a larger area. That combination fills the early P-waves with ground motion that is large in size but dominated by longer periods, meaning lower frequencies. So the P-waves from big quakes carry high amplitude at lower frequencies. Smaller quakes don’t show that same level of energy or long-period content, which is why this pairing doesn’t fit as well.

Strong earthquakes release a lot of energy, and the rupture lasts longer over a larger area. That combination fills the early P-waves with ground motion that is large in size but dominated by longer periods, meaning lower frequencies. So the P-waves from big quakes carry high amplitude at lower frequencies. Smaller quakes don’t show that same level of energy or long-period content, which is why this pairing doesn’t fit as well.