Science of earthquakes
On the 11th of March 2011, people from all around the world were shocked by the extent of geological destruction Japan was facing. Japan had been struck by a powerful earthquake of 9.0 in magnitude, which was the most powerful earthquake recorded in the country. Massive tsunami waves, some of those reached approximately 38 meters in height, were triggered as a result, engulfing many coastal areas of the country. The devastating event resulted in widespread destruction on land and a nuclear power plant was also heavily damaged, yielding a direct economic loss amounting to around $360 billion.
Science of Earthquakes
An intensive shaking of the surface of Earth is known as an earthquake. When the Earth’s outermost layer moves, such shaking is induced. On the outside, the Earth seems like a solid place. However, it is very active just below the surface. The outermost later is part of a region, known as the lithosphere, out of many. The lithosphere is not a continuous piece of sheet that wraps around the Earth. Instead, it is made up of multiple giant puzzle bits known as tectonic plates. These plates constantly move around due to thermal movement happening underneath them. However, earthquakes are not generally caused by the moving of these tectonic plates. When moving, tectonic plates may be locked together due to friction or other forces resisting the relative motion of the plates. However, in this case, the rest of the plates continue to move, causing the locked section, fault line, and surrounding area to deform. When an object deforms elastically, there exists elastic strain energy. However, when the forces resisting the relative motion are less than the forces causing the movement, the plates move past each other, releasing the deformation and strain energy as a result, causing an elastic rebound, resulting in energy being released in the form of seismic waves.
Understanding Tsunamis
Earthquakes happening on the ocean floor result in tsunamis. As an oceanic tectonic plate is forced down into the layer directly underneath by an overriding plate due to plate tectonic forces, friction occurs between the tectonic plate and overriding plate. This friction is enormous in magnitude, preventing the tectonic plate from being directed downward. In the similar case, elastic strain energy is stored in the plates in the deformed parts until the friction is overcome, upon which the overriding plate returns back to its original position as energy is released. The release of this energy causes the development of a tsunami.
Earthquake-prone Areas
The most active earthquake zone is the Pacific Plate that is considered to be the “Ring of Fire” and include Indonesia, Japan, New Zealand, Alaskan peninsula and the North and South America, many of those lie close to the plate. Another country is Italy that lies along the boundary of the African and Eurasian Plates.
However, a country may also be subject to earthquakes, although it is far away from the boundary of the plate on which it sits. Australia, located a distance away from the edges of the Indo-Australian Plate, experienced a 5.7 earthquake in the year of 2012. That was due to the building up of compressive deformation and the subsequent rupture of the earth’s crust, both of which occurred in the inner plate. Hence, if you are situated in a country where the possibility of occurrence of an earthquake is low, it is still better to get insured against such disasters. If you live in Australia and are intended to get an insurance for your business, given the number of insurance options available, it is suggested that you compare business insurance quotes online with iSelect to make sure that you get yourself correctly insured.