The most common source of a tsunami is an earthquake, although it can also be brought on by a meteorite, landslide, volcanic eruption, or abrupt changes in atmospheric pressure.¹⁾

A “wave train”—a series of waves collectively known as a tsunami—is what causes a tsunami. The “wave period,” which can last anywhere from a few minutes to two hours, is the interval between waves. Typically, the initial wave is not the strongest, and subsequent waves, like the fifth or sixth, may be much bigger.²⁾

For the first time, Greek historian Thucydides (460–395 B.C.) connected undersea earthquakes to tsunamis in his History of the Peloponnesian War.³⁾

Tsunami waves frequently only reach heights of one to three feet in the deepest parts of the ocean. It's possible for sailors to be completely unaware that a tsunami is passing under them.⁴⁾

Within 160 miles (250 km) of the tsunami's origin or within 30 minutes of the tsunami's generation, around 99% of all tsunami-related fatalities have occurred. Therefore, everyone in a coastal location should heed the natural signal that a tsunami may be approaching and escape low-lying coastal areas if they experience a significant earthquake.⁵⁾

The ocean may suddenly seem to drain away up to 30 minutes before a tsunami hits, although this is not always the case. The term “drawback” refers to the water receding as the tsunami's crest approaches the beach.⁶⁾

Hawaii, Alaska, Washington, Oregon, and California are the U.S. states most at risk from tsunamis.⁷⁾

On May 22, 1960, a massive earthquake struck more than 100 miles off the coast of Chile. 80-foot waves hit the beachfront within 15 minutes after the 9.5 quake. Hawaii was hit by tsunami waves fifteen hours after the earthquake, while Japan was hit by the tsunami 22 hours later, 10,000 miles away.⁸⁾

No one has ever seen a meteorite-induced tsunami, but many scientists believe that such an event may have wiped out all life on Earth more than 3.5 billion years ago.⁹⁾

While the speed of wind-generated waves can range from 2 to 60 miles (3.2 to 97 km/h), the speed of a jet airliner, tsunami waves can reach 600 miles (970 km/h).¹⁰⁾

The Indian Ocean was reportedly hit by an asteroid some 4,800 years ago, according to scientists. It is estimated that the resulting wave was around 600 feet (180 m) high.¹¹⁾

When a lighter tectonic plate is driven over a heavier plate or along subduction zones, tsunamis are caused by earthquakes. The whole water column above the ocean floor is moved by a quick rise or decrease in the ocean floor. A tsunami is caused by the ocean's level fluctuating above the earthquake. In most cases, if the tectonic plates split apart or glide past one other, a tsunami won't form.¹²⁾

With their long, exposed trunks, palm trees are perfectly suited to life on the beach and frequently survive tsunamis unharmed.¹³⁾

More than 216,000, and potentially as many as 283,000, people perished in the 2004 Indian Ocean tsunami.¹⁴⁾

The region of inundation is the furthest inland (horizontally) point that is inundated by tsunami waters.¹⁵⁾

The run-up is the name given to the vertically highest point that the water reaches.¹⁶⁾