Which of the following is NOT a word used to describe an earthquake?

The story behind the answer

Drop-slide is not a recognized earthquake term. Seismology uses “strike-slip” to describe horizontal motion along a fault (like the San Andreas), “foreshock” for a smaller quake that precedes the mainshock, and “temblor” as a common synonym for earthquake. There is a real term “dip-slip” (not drop-slip), which involves vertical motion along a fault.

To remember: strike-slip = sideways “strike,” dip-slip = motion along the fault’s dip (up/down), and temblor comes from Spanish “temblar” (to tremble). If you see “drop-slide,” think “that’s a made-up mashup”—the correct vertical term is dip-slip.