Which natural hazard is most directly caused by seafloor displacement due to tectonic activity triggering waves?

• A. Earthquakes
• B. Floods
• C. Tsunamis
• D. Landslides

Answer: (C)

When tectonic forces move the seafloor, they push water upward or downward, sending a huge wave train across the ocean. These waves, called tsunamis, are born from vertical displacement of the sea floor, not from the usual surface shaking. In deep water they travel fast with long reach but small height, and as they reach shallower coastlines they slow and rise dramatically, becoming destructive near shore. Earthquakes are the tectonic trigger that can initiate such displacement, but the hazard described is the waves themselves—tsunamis. Floods and landslides involve different processes, so they don’t fit the direct mechanism of seafloor displacement creating waves.