Biggest earthquakes in history

The most powerful earthquakes ever recorded by instruments, ranked by moment magnitude. All of the top events happened along subduction zones, where one tectonic plate dives beneath another.

Magnitude is logarithmic: each whole number is about 32 times more energy released. That is why a M9.5 like Valdivia dwarfs even a devastating M7.0 such as Haiti. But as Haiti and Lorca show, the death toll depends on depth, population and building quality — not magnitude alone.