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In my previous post,I introduced the concept of plate TECTONICS to you guys. This is a continuation and we'll be looking at plate tectonics as it relates to us. Hence, we'll be taking a brief look at earthquakes.
Lithospheric plates are brittle;they rupture when stresses are applied;very high stresses causes ruptures in the lithospheric plates and these ruptures are violent,and are known as Earthquakes.
Most Earthquakes are violent releases of seismic waves due to sudden displacement in the fault zone. Notable areas dominated by earthquakes and are located along narrow zones known as SEISMIC ZONES. A plate may be as broad as 10,000km for example, the Pacific plate or as small as a few 1000km for example the Philippines plate.
Earthquakes are known to occur around certain areas prone to volcanic eruptions. Examples are:
• Circum Pacific Ring of Fire: This zone makes a curve across the Pacific coast line,running from the southern margin of South America across the Pacific ocean to the North West coast of North America into Alaska and Eastern coast of Australia.
[source](https://en.m.wikipedia.org/wiki/File:Pacific_Ring_of_Fire.svg)
• Azore-North Africa Alphine-Dinaride-Himalaya-South East Asia: From North Africa,cuts across Italy.
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• World system of oceanic ridges:
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It's this seismic zone that delinates the lithosphere laterally into about twelve major tectonic plates and three minor tectonic plates,making a total of fifteen. They include:
MAJOR
Earthquakes are recorded by instruments called seismographs . The recording they make is called a seismogram. The size of the earthquake is called its
magnitude. Earthquakes cannot be predicted,but a method known as triangulation helps to tell the exact location of an earthquake that occurred. It takes three seismographs to locate an earthquake. When you draw a circle on a map around three different seismographs where the radius of each is the distance from that station to the earthquake, the point where all three lines intersect is the epicenter.
Earthquakes do not happen in my country Nigeria, because we have stable lithospheric plates beneath us.
PS: I'm proud to be a Nigerian.
Thanks for reading, please do leave a comment.