Five facts about tsunamis: what you should know about the dangerous phenomenon

SSPDaily has prepared five facts about tsunamis. Learn about the amazing features of this destructive element.

Impressive speed and distance covered by a tsunami

Tsunamis are impressive for their extreme speed and huge range. Despite the fact that tsunamis are a spontaneous and unpredictable phenomenon, their height and speed increase exponentially as they approach land. Moving at 700 km/h, these colossal waves can cover distances of more than 17,000 km, crossing vast expanses of ocean at breathtaking speeds.

Many waves in a tsunami

Contrary to popular belief, tsunamis do not come alone, but often bring with them a series of consecutive waves. This fact amplifies the destructive effects of tsunamis, which contradicts the usual idea of a single tidal wave. Their recurring nature causes more significant damage and problems for the affected regions.

Causes of the phenomenon

Although it is generally accepted that earthquakes are the main provocateurs of tsunamis, significant shifts in tectonic plates are not their exclusive catalyst. Many people are unaware that a meteorite or asteroid hurtling toward the Earth can cause this phenomenon. A striking example of this is the case that occurred about 3.46 million years ago, when an asteroid caused a global tsunami on our planet.

In addition, volcanic eruptions cause about 5% of all tsunamis. Large underwater eruptions have the same effect as earthquakes. A classic example is the tsunami that occurred during the 1883 eruption of Mount Krakatoa. At that time, in the vicinity of Java and Sumatra, the wave height reached 35-40 meters, and tsunamis were observed in Ceylon, off the southern coast of Africa, and at Cape Horn (South America). Moreover, near the latter, two waves were observed almost simultaneously: one circled the globe from east to west, and the other in the opposite direction.

The unexpected scale of the Japanese tsunami

On March 11, 2011, a triple disaster struck Japan: one of the most powerful earthquakes in the history of seismology brought a devastating tsunami and the largest since the Chernobyl nuclear power plant accident. These disasters killed nearly 20 thousand people and forced 470 thousand more Japanese to leave their homes.

Tsunami warnings

Although it is quite difficult to detect a tsunami, a sudden retreat of water from the shore, preceding the wave, can serve as a certain warning of its arrival.

A fairly effective way to determine the danger of a tsunami is to observe the water level with a tide gauge (a device for automatically recording water level fluctuations). Significant rises in water levels in areas close to the earthquake zone indicate a threat to the population of coastal areas.

It should be noted that tsunami warnings and precautions are taken by the Pacific Tsunami Relief Center, which is headquartered in the charming city of Honolulu.