1. Tsunami

2. WHAT IS IT? A tsunami is a series of water waves caused by the displacement of a large volume of a body of water. Tsunami is a complex event involving a group of high-energy waves of variable size that occur when scrolling vertically an extraordinary phenomenon a large body of water. Such waves remove a much higher amount of water surface waves produced by the wind. It is estimated that 90% of these phenomena are caused by earthquakes, in which case they are called more correct and accurate "tectonic tsunamis.“ HOW DOES IT HAPPEN? Earthquakes are the mostly cause of tsunamis. For an earthquake originates a tsunami, the sea floor abruptly be moved vertically, so that the ocean is driven outside its normal balance. When this huge water body tries to regain its balance, the waves are generated. The size of the tsunami is determined by the magnitude of the vertical deformation of the seafloor. Not all earthquakes generate tsunamis, but only those of considerable size (first condition), which occur below the seabed (second condition) and are able to deform (third condition). WHEN? Tsunamis are caused by an underwater, earthquake, a volcanic eruption, an sub-marine rockslide, or, more rarely, by an asteroid or meteoroid crashing into in the water from space.

3. WHERE? Most tsunamis, about 80% occur in the Pacific Ocean, on the Ring of Fire, a geologically active area where tectonic shifts make volcanoes and earthquakes are common.

4. The earthquake was caused by subduction and triggered a series of devastating tsunamis along the coasts of most landmasses bordering the Indian Ocean, killing over 230,000 people in fourteen countries, and inundating coastal communities with waves up to 30 meters (98 ft) high.] It was one of the deadliest natural disasters in recorded history. Indonesia was the hardest-hit country, followed by Sri Lanka, India, and Thailand.

5. EXAMPLE The 2004 Indian Ocean earthquake was an undersea mega thrust earthquake that occurred at 00:58:53 UTC on Sunday, 26 December 2004, with an epicentre off the west coast of Sumatra, Indonesia. The quake itself is known by the scientific community as the Sumatra–Andaman earthquake. The resulting tsunami was given various names, including the 2004 Indian Ocean tsunami, South Asian tsunami, Indonesian tsunami, and the Boxing Day tsunami.

6. HOW TO PREVENT: A tsunami can occur at any time of the day by an undersea earthquake. Experts believe that an earthquake of this magnitude, near the coast of Chile, can impact coastal areas closest among the first 5 to 35 minutes after the earthquake, giving very little time for the authorities to alert population. This is why it takes much importance that people know how they should react to a tsunami warning in our country. WHAT TO DO IN CASE OF: If you live in a coastal area and present some of the signs that a tsunami may occur, must follow these guidelines. It is very important to remain calm so as not to endanger his life and that of those around him. The first thing to do is seek shelter at heights above 30 meters. If instead you live in the hills there, the upper floors of a building (5th floor) or a thick forest can be an alternative protection. Do not expect to get a tsunami alert, go to a height zone barely possible.