As Japan Faces Tsunami Danger, Here Is How The Waves Form And What People Can Expect

Today, https://www.independent.co.uk/asia/japan/japan-earthquake-tsunami-warning-kumamoto-live-updates-b3022781.html" rel="noopener noreferrer" target="_blank">a 7.1 magnitude earthquake in Japan has struck https://www.independent.co.uk/topic/kumamoto">Kumamoto on the southern main island of Kyushu.

The Japan Meteorological Agency said a tsunami warning for waves measuring up to 1m was now in place following the earthquake and locals have been advised to be incredibly careful.

The Japanese government has issued emergency earthquake warnings for prefectures across Kyushu island, including Nagasaki, Kagoshima, Fukuoka, Saga, Oita, Miyazaki and Kumamoto itself.

What exactly are tsunamis?

According to the https://www.noaa.gov/education/resource-collections/ocean-coasts/tsunamis" rel="noopener noreferrer" target="_blank">National Oceanic and Atmospheric Administration: “A tsunami is a series of extremely long waves caused by a large and sudden displacement of the ocean, usually the result of an earthquake below or near the ocean floor.”

This force then creates waves that “radiate outward in all directions away from their source, sometimes crossing entire ocean basins.”

Unlike the wind-driven waves that we are used to seeing, tsunamis move throughout the entire ocean – from the ocean floor right to the surface. 

What causes tsunamis?

According to the https://www.tsunami.gov/?page=tsunamiFAQ" rel="noopener noreferrer" target="_blank">U.S Tsunami Warning System, 88% of tsunamis in the https://www.ncei.noaa.gov/products/natural-hazards/tsunamis-earthquakes-volcanoes/tsunamis" rel="noopener noreferrer" target="_blank">Global Historical Tsunami Database were generated by earthquakes or landslides caused by earthquakes.

However, they can also be caused by volcanic activity, underwater landslides or even by the impact of a large meteorite plunging into an ocean, according to https://www.nationalgeographic.com/environment/article/tsunamis" rel="noopener noreferrer" target="_blank">National Geographic.

What happens when tsunamis hit land?

While evacuations may seem like an extreme measure, the https://www.weather.gov/safety/tsunami-about" rel="noopener noreferrer" target="_blank">National Weather Service explains that tsunamis don’t need to be record-breaking to cause lasting harm.

They say: “A tsunami can be very dangerous to coastal life and property.

It can produce unusually strong currents, rapidly flood land and cause great destruction.

The flow and force of the water and the debris it carries can destroy boats, vehicles, and buildings and other structures; cause injuries; and take lives as the tsunami moves across the land.

“It only takes six inches of fast-moving water to knock over an adult and two feet of fast-moving water to carry away most vehicles.”

Alarmingly, even once the waves retreat to the ocean, they can still be incredibly dangerous: “The https://www.huffingtonpost.co.uk/news/water/">water can be just as threatening (if not more so) as it returns to the sea, taking debris and people with it.

Flooding and dangerous currents can last for days.”

What you should do if a tsunami warning is issued

While tsunamis are very unlikely in the UK, if a warning is issued while you’re abroad, ensure that you follow all government advice.

https://www.redcross.org/get-help/how-to-prepare-for-emergencies/types-of-emergencies/tsunami.html?srsltid=AfmBOooeSnc29bb_I5p0zN_gf0a63IThdz4BkV9yFiV3HGTXA5QLOGhG" rel="noopener noreferrer" target="_blank">The American Red Cross has a guide for tsunami warnings if you’d like to be prepared in case of tsunami.