Tsunami’s alerts were broadcast in Pacific parts on Wednesday after an earthquake of 8.8 magnitude of the Far East of Russia.
Here are key facts about tsunamis and the damage they can cause:
Water shock
A tsunami is a water shock that extends through the sea, usually triggered by a strong earthquake under the bottom of the ocean.
The sudden and violent movement of the earth’s crust can push or drive through a section of the seabed, with the crack displacing large amounts of water that move like waves.
The tsunamis radiates in all directions from their source and can cover huge distances, sometimes at the speed of a reaction plane.
They are a rare phenomenon, but they can create dangerously powerful currents and cause fatal floods in coastal areas.
Other causes
Large earthquakes are the main driver of tsunamis, but the phenomenon can also be caused by other cataclysmic geographical events, such as volcanic eruptions and landslides.
In 1883, a volcano broke the Pacific Island of Krakatoa, causing an explosion that could be heard 4,500 kilometers (2,800 miles) away, followed by a Tsunami that killed about 30,000 people.
The great storms or a meteorite that falls in the ocean can also be powerful enough to cause a tsunami, according to the national and national atmospheric administration of the United States.
‘Harbor wave’
The word “tsunami” comes from Japanese words for “port” and “wave”. Tsunamis are sometimes known as “tide waves”, but experts say this is inaccurate because they are not related to tides.
At their generation point, tsunamis have a relatively small wave height, with very separate peaks.
As the waves approach the shore, they are compressed by the bottom of the sea, reducing the distance between the peaks and greatly increasing the height.
When they reach the coast, Tsunami waves can hit repeatedly for several hours, or even days.
Roman historian
For those on the shore, the first sign of something bad can be the removal of the sea, which is followed by the arrival of large waves.
“The sea was returned back, and its waters flowed to the point that the deep sea background was exposed and many types of sea creatures could be seen,” Roman author Ammianus Marcellinus wrote from a tsunami that hit Alexandria in 365 AD.
“Huge masses of water flowed back when I least expected, and now overwhelmed and killed many thousands of people … Some large ships were thrown by the fury of the waves to the roofs.”
How much damage?
Several factors determine the height and destructiveness of a tsunami. They include the size of the earthquake, the volume of displaced water, the topography of the bottom of the sea and if there are natural obstacles that moisten the clash.
The Pacific Ocean is particularly prone to earthquakes and, therefore, to tsunamis, but during the millennia, tsunamis have occurred in many parts of the world.
The tsunami of December 2004 in the Indian Ocean was caused by an earthquake of magnitude of 9.1 on the Indonesian island of Sumatra.
He launched energy equivalent to 23,000 of the atomic bombs fallen in Hiroshima, according to the United States Geological Service (USGS). Around 220,000 people in 11 nations were killed, many of them thousands of kilometers from the epicenter.
