The Earth’s crust is made up of a dozen plates from an average 70 km thick, floating in an ocean of liquid rock, called Magma. These plates, called Tectonic plates, are moving themselves since millions years ago and gave the shape to the surface of our planet. Normally, these movements are imperceptible. But in some cases the plates collide each other like giant icebergs of land, blocking their displacement. When this happens, it begins to accumulate large energy, which at some point is released. This release of stored energy is called Earthquake. The edges of these plates are called Faults, 90% of this events are produced over this Faults. An Earthquake has a Focus, that is the point at the depth of the Earth where energy is released. And an Epicenter, which is the point on the surface of the Earth, located directly above the focus. Earthquakes are usually measured using two scales. The scale of Richter and the Scale of Mercali. The Richter scale is based on the seismographic record. Is a scale that grows exponentially, so that each point increase can mean an energy increased 10 times or more higher. For example, an earthquake of magnitude three is not perceived by people. One of magnitude 8 or greater, causes catastrophic damage. Mercali scale, not based on seismic records, but the damage produced in structures and the sensation perceived by the people. A magnitude of grade 9 of this scale, consider extensive damage to buildings, partial collapse, and panic. When an earthquake has an epicenter in the ocean, this causes huge movements of water called Tsunamis. Tsunamis are huge waves that can travel over 375 miles per hour. Offshore wave height is small, but when it reaches the coast, finding shallow depth, can reach heights of 100 feet or more. Tsunamis are formed by several waves that arrive separated by 15 to 20 minutes, causing devastation and death on the coast where it hits. The most important Earthquake in history occurred on May 22 1960 in the town of Valdivia. Chile. With a magnitude of 9.5 on the Ritcher scale. We are Explainers. We explain everything.