What type of faulting is most likely to lead to a destructive tsunami?

• A. Normal fault
• B. Reverse
• C. Strike-slip fault
• D. Oblique-slip fault

Answer: (B)

Large, destructive tsunamis are produced when the seafloor is abruptly uplifted by an earthquake. This vertical movement displaces a huge column of seawater, creating waves that radiate across the ocean. The most effective mechanism for this kind of seabed motion is reverse (thrust) faulting, typical of subduction zone earthquakes, where the hanging wall moves up relative to the footwall along a dipping fault. The rapid uplift over a broad area pushes water upward, generating a tsunami with the potential to become highly destructive when it reaches coastlines. In contrast, motions that are primarily horizontal, or involve less vertical displacement, produce much smaller or negligible tsunamis, which is why reverse faulting stands out as the most likely cause of a destructive tsunami.