Tsunamis and how they come to be
Tsunamis are some of the most extreme weather related events on the planet influencing almost every aspect of our society. Picture a wall of water as tall as a building moving toward you, and you can only go in one direction. However, how do these massive walls of water start? The majority of tsunami's initiate from large earthquakes that occur within the subduction zone on the ocean floor. Within the subduction zone, plates are moving against one another as one plate moves beneath another plate, sinking into the Earth's mantle (convergent plate boundary). When these tectonic plates collide beneath the sea floor, enormous energy is released, thereby displacing the water and creating a wave (in general, it takes an earthquake to measure 7.0 or higher for a substantial tsunami to occur). Tsunami's can also occur from underwater landslides caused by earthquakes. Now, as the wave moves farther away from the epicenter of the earthquake, it generally loses energy which is why tsunamis that occur closer to land, cause more destruction than tsunamis to occur in the open ocean. As can be seen in the figure below, the subduction zones are located in and along the coastal regions of the Pacific Ocean (also known as the ring of fire). The ring of fire (which moves along the eastern part of Asia, southern part of Alaska and western parts of North and South America) observes the greatest amount of large magnitude earthquakes on earth, thus creating the largest amounts of tsunamis. Japan which is one of the most noticeable locations for earthquake and tsunami activity has multiple convergent boundaries surrounding the island making it experience one of the largest amounts of seismic related events. Volcanic activity is also largely associated to convergent boundaries.