The phenomenon of rare tidal waves appears in Japan

The strong earthquake that caused tsunamis in eastern Japan on November 21 did not cause significant damage and casualties, but it caused a rare interesting phenomenon called "estuary waves".

The videos capture the phenomenon of the estuary waves throughout the news and social media sites on November 22. So what is the cause of slow moving waves on rivers and canals?

According to Andy Newman, associate professor and geophysicist at the Georgia Institute of Technology, "the tsunami appears quite similar to the tide, possibly including estuarine wave structures."

The phenomenon of estuarine waves appears after the recent earthquake and tsunami in Japan.(Photo: CNN).

In the past, tsunamis were often considered tidal waves, but this is not true because tsunamis are not related to real waves, but are caused by earthquakes or Earth's movements such as erosion. land.

Estuary tidal waves are created when a massive wave of waves rushes into a funnel as it flows into long, narrow rivers and canals, creating a slow-moving wave in the upstream direction.

There are a number of places on Earth, due to local geographical characteristics, often present with large tidal estuaries, such as Canada's Bay of Fundy, River Severn in England, and Tien Duong River in Eastern China. During the biggest waves - for example on the full moon - the tidal wave attracted many crowds and even experienced veteran surfers.

Although the tidal wave caused by tsunamis is not as dangerous as when the tsunami really landed, this phenomenon can still have a significant impact on the internal waters.

Newman said: "River tidal waves can move many kilometers deep into the inner area, and can carry careless people upstream, damaging the jetty in the river."