Underwater earthquakes in the Pacific and Indian oceans are not uncommon, but rarely do they trigger deadly tsunamis like the killer waves spawned in the Indian Ocean in December 2004. Many factors can determine whether a tsunami is generated — one being earthquake power. Below, a look at how three significant underwater temblors stack up against each other in power.
The U.S. Geological Survey has an online calculator
to compare earthquakes' relative magnitudes.