Tsunamis are caused by the sudden vertical displacement of the seafloor. Thrust or reverse faults, common at subduction zones, push one block of crust upward. This vertical “kick” moves the entire water column above it, creating the massive energy pulse that becomes a tsunami. ANSWER: (C) Thrust/Reverse fault
Which type of fault is most likely to produce a Tsunami? (A) Strike-slip fault (B) Normal fault (C) Thrust/Reverse fault (D) Horizontal fault
Share
Strike-slip faults (like the San Andreas) involve horizontal sliding, which doesn’t displace much water vertically and thus rarely triggers tsunamis. However, at “Megathrust” boundaries, the overriding plate snaps upward during an earthquake. This act is like lifting the bottom of a bathtub; the water has no choice but to move. The resulting wave carries the energy of the entire displaced water column. This is why the world’s most destructive tsunamis, like those in 2004 and 2011, are always associated with subduction zone thrust-faulting.