With the ability to approach shores at 30 miles an hour and rise more than 100 feet high, tsunamis pose a deadly threat to coastal populations. The 2004 Indian Ocean tsunami and the 2011 Tohoku tsunami are two vivid and tragic examples of these waves' destructive power.

The most important step in staying safe during a tsunami—or any natural disaster, for that matter—is to know how vulnerable your area is in the first place. Many local governments map hazard areas and evacuation routes for communities at risk, while the U.S. National Weather Service offers a nationwide map with links to resources.

"Know what your risks are," says Kevin J. Richards, a natural hazards officer for the Hawaii Emergency