Breakdown: Why Tsunamis are devastating to coastal towns

Breakdown: Why Tsunamis are devastating to coastal towns

MEMPHIS, TN (WMC) - A 7.5 magnitude earthquake struck the Indonesian Island of Sulawesi on September 28th. The rather strong earthquake triggered a tsunami. The earthquake and tsunami resulted in hundreds of deaths as the water pounded the coast of Indonesia.

In this breakdown, we explain what a tsunami is and why they can be destructive and deadly.

According to the National Ocean Service, tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea.

Tsunami example graphic from NOAA
Tsunami example graphic from NOAA (NOAA)

In the depths of ocean, tsunami waves to not dramatically increase height. But as they move inland, the build up to higher and higher heights as the depth of the ocean decreases.

How a Tsunami Works from NOAA
How a Tsunami Works from NOAA (NOAA)

The speed of the tsunami wave is more dependent on ocean depth rather than the distance from the source of the wave.

In fact, tsunamis can travel as fast as a jet plane over deep waters, only slowing down some when they reach shallower waters.

While some people call tsunamis “tidal waves”, that is actually discouraged by oceanographers because tides have little to do with these giant waves.

“Tsunami” comes from the Japanese characters for harbor (“tsu”) and wave (“name”).

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